Polona Hercog

Polona Hercog (, born 20 January 1991) is a Slovenian professional tennis player. Her career-high WTA rankings are 35 in singles and 56 in doubles. She has won five titles on the WTA Tour, three in singles and two in doubles. Hercog also has had success on the ITF Women's Circuit, winning 19 singles and five doubles titles.

Partnering with Jessica Moore, she won the French Open and Wimbledon Championships junior titles in the doubles competition in 2008.

Early and personal life
Hercog was born in Maribor, Slovenia, to florist Romana and bar owner Vojko. As a four-year-old she began playing in the local tennis clinic opened by Mima Jaušovec, and at age 14 moved to Italy to train professionally. Hercog is fluent in Slovenian, English, and Italian, and cites Justine Henin as her role model. She currently resides in her hometown and practises in Budapest.

Junior career
In 2008, Hercog reached the singles quarterfinals at both the junior French Open and Wimbledon. In doubles, she and Australian Jessica Moore won two Grand Slam titles together, the French Open and Wimbledon; the latter was the final tournament of her junior career. On 7 July, Hercog achieved a career-high ITF junior ranking of No. 8.

2007–2009
In September 2007, Hercog received a wildcard and made her WTA Tour debut at the Slovenia Open, losing to Elena Vesnina in three sets. In early 2008, she won two ITF $10k titles and reached the final of an ITF $25k. Hercog then participated in the İstanbul Cup, coming through qualifying to reach the main draw, where she lost in the first round to eighth seed Tsvetana Pironkova. At the same tournament, she reached the final of the doubles competition partnering with New Zealand's Marina Erakovic. Ranked No. 215, she made her Grand Slam debut in the qualifying competition of the US Open, losing to Sandra Záhlavová in the first round.

In April 2009, Hercog entered the Morocco Open in Fes via qualifying, defeating seventh seed Roberta Vinci to reach the quarterfinals, where she lost to second seed Alisa Kleybanova. At that year's French Open, she qualified for the main draw and upset 23rd seed Kleybanova before losing to Aravane Rezaï in the second round. On 5 July, she debuted in the top 100 of the rankings for the first time at No. 89. At the US Open, Hercog was beaten by American wildcard Christina McHale in the first round. She also played the Luxembourg Open, defeating Maria Elena Camerin in the opening round. She then lost to Sabine Lisicki in two sets. Hercog reached the second round of the 2009 Allianz Cup in Sofia, losing to Bojana Jovanovski.

2010
Hercog began her season at the Auckland Open where she lost to Shahar Pe'er in the first round.

At the Mexican Open in Acapulco, Hercog reached her first WTA Tour singles final and won her first WTA doubles title. She defeated Rossana de los Ríos in the first round, Alizé Cornet in the second, Ágnes Szávay retired from the quarterfinals match when Hercog was leading by a set, and Carla Suárez Navarro in two sets in the semifinals. In the final, she lost to top seed and former world No. 1, Venus Williams, despite winning the first set. Partnering with Barbora Záhlavová-Strýcová, she won her first tour doubles title, beating the Italian duo Sara Errani and Roberta Vinci.

At the Indian Wells Open, Hercog defeated Raluca Olaru in the first round and was defeated by 11th seed Marion Bartoli in the second round. She caused an upset in the second round of the French Open by defeating No. 24, Lucie Šafářová.

In Portorož, she reached the semifinals, was up a set against Anna Chakvetadze but then lost the match in three sets. Seeded sixth at the Danish Open in Copenhagen, she had a chance to take revenge on Anna Chakvetadze as they met in the quarterfinals. Hercog lost the match, this time in straight sets.

2011
Hercog began the year at the Brisbane International where she lost in the first round to Iveta Benešová in two sets. Seeded second in qualifying at the Sydney International, Hercog lost in the first round to Jill Craybas. At the Australian Open, she lost in the first round in a close match to world No. 46, Anastasija Sevastova.

After the Australian Open, Hercog played at the 2011 Fed Cup World Group II against Germany. She defeated Julia Görges, however, she lost to Andrea Petkovic in straight sets. Slovenia lost to Germany 1–4. Seeded second at the Copa Colsanitas, she defeated Pauline Parmentier in the first round. In the second round, she lost to Petra Martić. Seeded second at the Abierto Mexicano, Hercog lost in the first round to Lourdes Domínguez Lino. She then stayed in Mexico for the Monterrey Open. Seeded eighth, Hercog defeated Angelique Kerber in the first round 6–3, 6–3. She then reached the semifinals where she lost to top seed Jelena Janković in two sets. At the Indian Wells Open, Hercog lost in the first round to Anastasija Sevastova. At the Miami Open, she lost in the first round to Chanelle Scheepers in three sets.

Hercog began her clay-court season at the Andalucia Tennis Experience. She lost in the first round to Laura Pous Tió, 1–6, 2–6. Next, Hercog played at the Morocco Open where she got revenge on Chanelle Scheepers by defeating her in the first round. However, she withdrew from her second-round match against Melanie Oudin due to an ankle injury. At the Barcelona Open, Hercog won her first-round match against lucky loser Jamie Hampton. In the second round, she easily beat Mirjana Lučić. In the quarterfinals, she lost to Laura Pous Tió in three sets.

2012
Hercog began the year at the Brisbane International. She retired trailing 6–1, 4–1 in her first-round match against seventh seed Anastasia Pavlyuchenkova due to a low back injury. Seeded third in qualifying at the Sydney International, Hercog lost in the final round of qualifying to seventh seed Ekaterina Makarova. However, she received a lucky loser spot into the main draw. In the first round, Hercog lost to eighth seed Marion Bartoli. At the Australian Open, she lost in the first round to 22nd seed Julia Görges.

After the Australian Open, Hercog represented Slovenia for Fed Cup against Japan. She lost both of her rubbers to Kimiko Date-Krumm and Ayumi Morita. Japan went on to defeat Slovenia 5–0. At the Open GDF Suez, Hercog lost in the first round to Chanelle Scheepers in straight sets. She suffered another first-round loss at the Qatar Open to Tsvetana Pironkova. Seeded second for qualifying at the Dubai Championships, she lost in the final round of qualifying to Aleksandra Wozniak. Entering the main draw as a lucky loser, Hercog lost in the first round to world No. 21, Daniela Hantuchová. Ranked 38 at the Indian Wells Open, she lost in the first round to wildcard Jamie Hampton, 0–6, 1–6. At the Sony Ericsson Open, Hercog got revenge on qualifier Jamie Hampton defeating her in the first round 6–1, 6–3. In the second, she lost to seventh seed Marion Bartoli.

Hercog began her clay-court season at Charleston. Seeded 14th, she beat Kimiko Date-Krumm in the first round and American Varvara Lepchenko in the second. In the third round, Hercog upset third seed Marion Bartoli. and in the quarterfinals, 13th seed Nadia Petrova, 6–1, 6–2 to reach the semifinals where she was crushed by ninth seed Lucie Šafářová, 6–0, 6–0. Seeded eighth at the Barcelona Ladies Open, Hercog retired in her first round match against Sorana Cîrstea after losing the first set 4–6 due to dizziness. Seeded ninth at the Estoril Open, she defeated Tamira Paszek in the first round 6–0, 6–3. In the second round, Hercog retired trailing 6–4, 3–0 to Carla Suárez Navarro due to a right foot injury. Ranked 37 at the Madrid Open, Hercog lost in the first round to Shahar Pe'er 3–6, 5–7. At the French Open, she was defeated in the first round by Ayumi Morita.

At Wimbledon, Hercog lost in the first round to qualifier Kristýna Plíšková.

After that, she competed at Palermo where she was upset in the first round by Irina-Camelia Begu. Hercog then played at the Swedish Open as the defending champion and prevailed again, defeating Mathilde Johansson in the final. Representing Slovenia at the London Olympics, Hercog was defeated in the first round by María José Martínez Sánchez.

She played one warm-up tournament before the US Open. At the Texas Open. She faced Kiki Bertens in the first round, and won the first set 6–4 when Bertens retired due to a right abdominal injury. In the second round, she lost to third seed and eventual champion Roberta Vinci. At the US Open, Hercog was defeated in the first round by fifth seed Petra Kvitová.

At the Korea Open, she lost in the first round to eighth seed Ekaterina Makarova. Seeded 11th for qualifying at the Pan Pacific Open, Hercog lost in the first round of qualifying to wildcard Kurumi Nara. She qualified for the China Open beating 17th seed Mathilde Johansson and Gréta Arn. In round one, Hercog led 5–7, 6–4, 3–0 before Anastasia Pavlyuchenkova retired due to a gastrointestinal illness. In the second round, she defeated Ekaterina Makarova in a very close match. In the third round, Hercog lost to second seed and eventual finalist Maria Sharapova. Her final tournament of the year was at the Osaka Open. She lost in the first round to eventual champion Heather Watson.

Hercog ended the year ranked No. 80.

2013
At the Australian Open, she was defeated in the first round by 21st seed Varvara Lepchenko.

Seeded 17th for qualifying at the French Open, she beat Ajla Tomljanović in the first round of qualifying, but in the second round she lost to Grace Min. After the French Open, Hercog played the 25k-tournament in Maribor, Slovenia. As the top seed, she won the tournament defeating Ana Konjuh in the final. At the 100k-tournament in Marseille, she was defeated in the semifinals by top seed Anabel Medina Garrigues. Competing at the first edition of the Nürnberger Versicherungscup, Hercog upset second seed Klára Zakopalová in the first round. In the second round, she beat Julia Cohen in two sets. In the quarterfinals, Hercog was defeated by fifth seed Lucie Šafářová.

Seeded fourth for qualifying at Wimbledon, Hercog lost in the second round of qualifying to Petra Cetkovská.

At Palermo, she was defeated in the second round by second seed Roberta Vinci. Hercog won the ITS Cup as the top seed beating Katarzyna Piter in the final. Seeded sixth at the Baku Cup, Hercog lost in the first round to Galina Voskoboeva.

Hercog qualified for the Cincinnati Open defeating ninth seed Lourdes Domínguez Lino in the final round of qualifying. In the first round, she beat world No. 19, Dominika Cibulková, 6–2, 6–4. In the second round, Hercog lost to sixth seed Sara Errani. At the US Open, Hercog was defeated in the first round by 24th seed Ekaterina Makarova.

At the Challenge Bell, she stunned top seed and defending champion Kirsten Flipkens in the first round 6–3, 6–1. In the second round, she beat qualifier Julie Coin 6–0, 6–2. In the quarterfinals, Hercog lost to Christina McHale. Hercog qualified for the Pan Pacific Open beating ninth seed Tsvetana Pironkova in the final round of qualifying. In the first round, she was defeated in a close match by world No. 35, Lucie Šafářová. Qualifying for the China Open, Hercog beat Monica Puig in the first round 6–1, 6–4. In the second round, Hercog upset 14th seed and former world No. 1, Ana Ivanovic. In the third round, she lost to third seed Agnieszka Radwańska. Her final tournament of the year was the Japan Open. In the first round, she beat Petra Cetkovská, and received a walkover in the second round since her opponent, second seed Sabine Lisicki, withdrew due to a hip injury. In the quarterfinals, Hercog was defeated by Kurumi Nara.

She ended the year ranked No. 66.

2014
Hercog began her season at the Australian Open. In the first round, she was up against 25th seed Alizé Cornet. Hercog retired trailing 1–0 due to a shoulder injury.

Hercog made her comeback during the clay-court season at the Morocco Open. In the first round, she upset Zhang Shuai 6–2, 6–2. In the second round, she defeated Alison Van Uytvanck 6–1, 6–4. Hercog was then stopped in the quarterfinals by eventual champion María Teresa Torró Flor in two tie-breakers. At the Portugal Open, she beat Stefanie Vögele in the first round. In the second round, she upset sixth seed Lucie Šafářová. Hercog lost in the quarterfinals to top seed and eventual champion, Carla Suárez Navarro. Seeded sixth for qualifying at the Italian Open, Hercog lost in the first round of qualifying to Belinda Bencic. Her final tournament before the French Open was the Nürnberger Versicherungscup. In the first round, she upset third seed Klára Koukalová in three sets. In the second round, Hercog lost to Karin Knapp. At the French Open, she defeated Jana Čepelová in the first round In the second round, Hercog was defeated by 15th seed Sloane Stephens 6–1, 6–3.

Hercog played only one grass-court tournament before Wimbledon. She lost in the first round at Rosmalen to sixth seed Kirsten Flipkens. At Wimbledon, she won her first round match over Paula Ormaechea. In the second round, she was defeated by 23rd seed Lucie Šafářová.

After Wimbledon, Hercog competed at the first edition of the Bucharest Open. Seeded eighth in the draw, she defeated Anna Tatishvili in the first round. In the second round, she beat Katarzyna Piter. In the quarterfinals, Hercog lost to Monica Niculescu. Seeded eighth at the Swedish Open, she lost in the first round to Dinah Pfizenmaier.

Hercog began the US Open Series at the Washington Open. She lost in the first round to sixth seed and eventual champion Svetlana Kuznetsova. Seeded 20th for qualifying at the Cincinnati Open, Hercog reached the main draw beating Paula Ormaechea and Julia Glushko. In the first round, she was defeated by Kirsten Flipkens, 6–3, 6–2. At the Connecticut Open, her final tournament before the US Open, Hercog lost in the second round of qualifying to Karin Knapp, 2–6, 1–6. Ranked 76 at the US Open, she defeated world No. 35, Elina Svitolina, in the first round in two sets. In the second round, she lost to 17th seed Ekaterina Makarova.

After the US Open, Hercog played at the first edition of the Hong Kong Open. She lost in the first round to third seed and eventual finalist, Karolína Plíšková. At the Korea Open, Hercog was defeated in the first round by top seed and defending champion Agnieszka Radwańska. Seeded 18th for qualifying at the first edition of the Wuhan Open, she lost in the first round of qualifying to Nicole Gibbs. Seeded 11th for qualifying at the China Open, Hercog qualified by defeating Yulia Putintseva and seventh seed Monica Puig. In the first round, she beat world No. 29, Karolína Plíšková. In the second round, Hercog lost to 12th seed Ekaterina Makarova. Seeded second for qualifying at the Generali Ladies Linz, she lost in the first round of qualifying to Lucie Hradecká. Her final tournament of the year was at the Luxembourg Open. She won her first-round match over Marina Erakovic 6–3, 6–4. Then Hercog was defeated by qualifier Johanna Larsson.

She ended the year ranked No. 95.

2015
Hercog started the year at the Shenzhen Open where she lost to Zheng Saisai in the second round. Coming through qualifying at the Sydney International, Hercog was defeated in the first round by Karolína Plíšková. At the Australian Open, she lost in the second round to qualifier Lucie Hradecká.

Seeded seventh at the Rio Open, Hercog was defeated in the second round by Brazilian wildcard Beatriz Haddad Maia. Playing in Acapulco at the Mexican Open, she lost in the first round to third seed and eventual finalist Caroline Garcia. Hercog stayed in Mexico to compete at the Monterrey Open. She was defeated in the second round by eighth seed Magdaléna Rybáriková. Hercog had multiple match points in the third set but failed to convert. Getting past qualifying at the Indian Wells Open, Hercog beat 2009 champion Vera Zvonareva in the first round. She lost in the second round to 25th seed Caroline Garcia. At the Miami Open, Hercog was defeated in the first round by Anna Karolína Schmiedlová. In Poland at the Katowice Open, Hercog lost in the second round to second seed and defending champion Alizé Cornet.

2016
Hercog began the year at Auckland where she lost in the first round to fifth seed and eventual champion, Sloane Stephens. In Sydney, she was defeated in the final round of qualifying by Monica Puig. However, she was awarded a lucky loser spot into the main draw. She lost in the first round to Sabine Lisicki. At the Australian Open, she was defeated in the first round by 19th seed Jelena Janković.

Seeded fifth at the Rio Open, Hercog lost in the second round to Sorana Cîrstea. Playing at the Mexican Open, she was defeated in the first round by top seed Victoria Azarenka. At the Monterrey Open, she lost in the second round to eventual champion Heather Watson. Competing in Indian Wells, she was defeated in the first round by Yanina Wickmayer. At the Miami Open, she retired during her first round of qualifying match against Fanny Stollár.

Hercog began her clay-court season at the Stuttgart Grand Prix. She lost in the final round of qualifying to German Laura Siegemund. At the Morocco Open, she was defeated in the first round by fifth seed and last year finalist Tímea Babos. In Madrid, she lost in the first round of qualifying to Madison Brengle. At the Italian Open, she was defeated in the first round of qualifying by Julia Görges. Her final tournament before the French Open was at Nürnberg where she lost in the second round to fourth seed Lesia Tsurenko. At the French Open, she was defeated in the second round by 30th seed Barbora Strýcová.

Seeded seventh at the Bol Ladies Open, Hercog reached the final which she lost to Mandy Minella.

Beginning her grass-court season at the Rosmalen Open, Hercog retired during her first-round match against Varvara Lepchenko. Coming through qualifying at the Eastbourne International, she was defeated in the first round by Misaki Doi. At the Wimbledon Championships, she lost in the first round to Alizé Cornet.

Competing at the Bucharest Open, Hercog made it to the quarterfinals where she was defeated by fourth seed Laura Siegemund. At the Swedish Open, she fell in the first round to Julia Görges. Representing Slovenia at the Rio Olympics, she lost in the first round to eventual gold medalist Monica Puig.

At the US Open, Hercog faced second seed Angelique Kerber in the first round. She retired from the match due to illness.

Due to not playing for the rest of the year, Hercog ended the year ranked 139.

2017
She returned to the tour for her first tournament since the 2016 US Open at the French Open. where she beat French wildcard Harmony Tan in the first round of qualifying. However, in the second round, Hercog lost to Zarina Diyas. At a $25k tournament in Grado, she lost in the first round to Diāna Marcinkēviča. Seeded seventh at the Internazionali di Brescia, she won the title, defeating Ganna Poznikhirenko in the final in two sets.

2019
Hercog began the year at the Auckland Open. She lost in the first round to third seed Hsieh Su-wei. In Hobart, she was defeated in the first round of qualifying by Olivia Rogowska. At the Australian Open, she lost in the first round to second seed and 2016 champion, Angelique Kerber.

As the top seed at the Andrézieux-Bouthéon Open, Hercog reached the semifinals where she retired after losing the first set against Rebecca Šramková. In Doha, she was defeated in the final round of qualifying by Ajla Tomljanović. However, due to the withdrawal of Ashleigh Barty, she entered the main draw as a lucky loser. In the first round, she lost to fellow lucky loser Alison Riske. At the Dubai Championships, she fell in the final round of qualifying to Lucie Hradecká. Since Caroline Wozniacki withdrew from the tournament due to a viral illness, she got a lucky loser spot in the main draw. She was defeated in the first round by lucky loser Stefanie Vögele. In March, she played at the Miami Open. Even though she lost in the final round of qualifying to Laura Siegemund, she still entered the main draw as a lucky loser. She reached the third round where she was eliminated by second seed Simona Halep.

Hercog won her third WTA singles title at the Ladies Open Lugano, defeating Iga Świątek in the final.

2020
Hercog kicked off the season at the Australian Open, where she lost in the second round to top seed Ashleigh Barty.

Playing at the Dubai Championships, she was defeated in the final round of qualifying by Kristina Mladenovic. In Doha, she lost in the first round to Alison Van Uytvanck. The WTA suspended tournaments from March through July due to the COVID-19 pandemic.

When the WTA resumed tournaments in August, Hercog competed at the Palermo Ladies Open. She was defeated in the first round by Italian wildcard Elisabetta Cocciaretto. At the Prague Open, she lost in a tight three-set first-round match to top seed and eventual champion, Simona Halep. She skipped both the Cincinnati Open and the US Open.

Seeded third at the İstanbul Cup, Hercog reached the quarterfinals where she was defeated by Paula Badosa. In Rome, she upset fifth seed Kiki Bertens in the second round. She fell in the third round to 12th seed Markéta Vondroušová. At the Internationaux de Strasbourg, she lost in the first round to 2013 champion Alizé Cornet. At the French Open, she was defeated in the second round by Leylah Fernandez.

Hercog played her final tournament of the season at the Dubai Tennis Challenge. Seeded second, she made it to the semifinal where she lost to Sorana Cîrstea.

Hercog ended the year ranked No. 52.

2021
Hercog started her season at the first edition of the Abu Dhabi Open where she lost in the first round to fourth seed and eventual champion, Aryna Sabalenka. Seeded 15th at the first edition of the Gippsland Trophy, she was defeated in the second round by Daria Kasatkina. At the Australian Open, she lost in the first round to Caroline Garcia.

Competing in Dubai, Hercog was defeated in the first round by lucky loser Misaki Doi.

As the top seed at the Oeiras Ladies Open, Hercog won the title when her opponent, fifth seed Clara Burel, withdrew from the match due to a left ankle injury.

At the İstanbul Cup, she lost in the first round to Vera Zvonareva. Despite losing in the final round of qualifying at the Madrid Open to Bernarda Pera, she still received a lucky loser spot into the main draw due to the withdrawal of Svetlana Kuznetsova. She was defeated in the first round by Jeļena Ostapenko. Getting past qualifying in Rome, she lost in the first round to 17th seed Maria Sakkari. At the first edition of the Serbia Open, she was defeated in the first round by Leylah Fernandez. At the French Open, she beat 16th seed and 2016 semifinalist, Kiki Bertens, in the first round. She ended up losing in the third round to 20th seed and 2019 finalist, Markéta Vondroušová.

At the Birmingham Classic, Hercog was defeated in the first round by fourth seed and eventual finalist, Daria Kasatkina. In Eastbourne, she fell in the first round of qualifying to Zhang Shuai. At Wimbledon, she lost in the first round to Danielle Collins. She also lost in the first round at the US Open, to tenth seed Petra Kvitová. Finally, she lost in the first round of the Indian Wells Open to Anastasija Sevastova, making her win–loss record 4–14 for the season, the worst in her 15-year professional career.

Hercog ended the year ranked 135.

Performance timelines
''Only main-draw results in WTA Tour, Grand Slam tournaments, Billie Jean King Cup /Fed Cup and Olympic Games are included in win–loss records. ''

Singles
Current through the 2021 Transylvania Open.