Lukáš Klein

Lukáš Klein (born 22 March 1998) is a Slovak professional tennis player. Klein has a career-high ATP singles ranking of World No. 116, achieved on 1 April 2024. He also has a career-high doubles ranking of World No. 240, achieved on 5 April 2021. He is currently the No. 2 Slovak tennis player in singles.

Klein has reached 15 career singles finals, with a record of 9 wins and 6 losses, including 3 ATP Challenger titles. Additionally, he has reached 11 career doubles finals, with a record of 5 wins and 6 losses, including a 1–3 result in Challenger finals.

2021: ATP & top 250 & Olympics singles & doubles debut
Klein won the doubles title at the 2021 Challenger La Manche with compatriot Alex Molčan 1–6, 7–5, [10–6].

Klein made his ATP main draw singles debut in March at the 2021 Argentina Open, where he defeated Andrea Collarini, Thiago Seyboth Wild and Ernesto Escobedo to qualify for the main draw. Klein then went on to upset compatriot Andrej Martin in straight sets. He would go on to lose in the second round to top seed, local favourite and eventual champion Diego Schwartzman in straight sets.

He reached the top 250 at World No. 248 in singles on 28 June 2021 after reaching the second round also as a qualifier at the 2021 Mallorca Championships by defeating 8th seed Dušan Lajović, for his second ATP win for the season and in his career.

At the Olympics, Klein was entered as an alternate for Matteo Berrettini, who had withdrawn due to a thigh injury. He also participated in the doubles event partnering Filip Polášek and reaching the second round.

2022: Maiden Challenger title, Major & top 150 debut
In May, he won his first Challenger at the 2022 Saturn Oil Open in Troisdorf, Germany as a qualifier without dropping a set.

He qualified for the 2022 Wimbledon Championships making his Grand Slam debut. He lost to wildcard Liam Broady in five sets.

He reached his second Challenger final in Alicante and won the title. As a result, he moved more than 40 positions up to a new career-high in the top 180 on 10 October 2022. Following his third final in Ortisei, Italy he moved 17 positions up into the top 150 at No. 146 on 31 October 2022.

2023-24: Masters debut, first Major and Masters wins, Slovak No. 1, top 125
He qualified for and reached back-to-back finals at the 2023 Sparkassen ATP Challenger in Ortisei, Italy. He won his third Challenger title defeating Maks Kaśnikowski.

In January 2024, he qualified for the 2024 Brisbane International and defeated sixth seed Sebastián Báez for his first ATP win of the season and only third in his career. Ranked No. 163, he qualified for the 2024 Australian Open making his debut at this tournament and recorded his first Major win over Kwon Soon-woo. In the next round, he took sixth seed Alexander Zverev to five sets before losing the match in a fifth set tiebreak.

He qualified for the 2024 BNP Paribas Open making his Masters debut and recorded his first win at this level over Nicolas Moreno de Alboran. As a result he moved to a new career high in the top 130 and became the Slovak No. 1 player. Next he qualified for another Masters, the 2024 Miami Open defeating Benoit Paire and Jakub Menšík. He lost to Alex Michelsen in the first round. As a result he reached the top 120 in the rankings at world No. 116 on 1 April 2024.

He qualified for his third Masters of the season at the 2024 Mutua Madrid Open and recorded his first win at the tournament and only second at this level, over fellow qualifier Pablo Llamas Ruiz before losing to 15th seed Tommy Paul.