2018 Oracle Challenger Series – Chicago

The 2018 Oracle Challenger Series – Chicago was a professional tennis tournament played on outdoor hard courts. This tournament was part of the 2018 ATP Challenger Tour and the 2018 WTA 125K series. The first edition took place from September 4 to 9, 2018 in Chicago, United States.

Seeds

 * 1 Rankings are as of 27 August 2018.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇺🇸 JC Aragone
 * 🇺🇸 Thai-Son Kwiatkowski
 * 🇺🇸 Tommy Paul
 * 🇮🇹 Andreas Seppi

The following players received entry into the singles main draw as alternates:
 * 🇩🇴 Roberto Cid Subervi
 * 🇺🇸 Ernesto Escobedo
 * 🇩🇪 Dominik Köpfer
 * 🇺🇸 Donald Young

The following players received entry from the qualifying draw:
 * 🇺🇸 Sekou Bangoura
 * 🇫🇷 Vincent Millot
 * 🇫🇷 Hugo Nys
 * 🇺🇸 Alexander Sarkissian

The following players received entry as lucky losers:
 * Ruan Roelofse
 * 🇯🇵 Kaichi Uchida

Seeds

 * 1 Rankings are as of 27 August 2018.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇺🇸 Danielle Collins
 * 🇺🇸 Lauren Davis
 * 🇺🇸 Francesca Di Lorenzo
 * 🇺🇸 Allie Kiick
 * 🇺🇸 Varvara Lepchenko

The following players received entry from the qualifying draw:
 * 🇨🇦 Françoise Abanda
 * 🇺🇸 Kristie Ahn
 * 🇺🇸 Robin Anderson
 * 🇺🇸 Irina Falconi
 * 🇧🇬 Sesil Karatantcheva
 * 🇺🇸 Jamie Loeb

Withdrawals

 * 🇺🇸 Jennifer Brady → replaced by 🇨🇳 Duan Yingying
 * Dalila Jakupović → replaced by 🇧🇷 Beatriz Haddad Maia
 * 🇺🇸 Vania King → replaced by 🇨🇳 Zhu Lin
 * 🇵🇱 Magda Linette → replaced by 🇺🇸 Madison Brengle
 * 🇺🇸 Christina McHale → replaced by Jana Fett
 * 🇷🇴 Monica Niculescu → replaced by 🇬🇧 Katie Boulter
 * 🇸🇪 Rebecca Peterson → replaced by 🇩🇪 Mona Barthel
 * Monica Puig → replaced by 🇹🇳 Ons Jabeur

Seeds

 * Rankings are as of 27 August 2018

Men's singles

 * 🇺🇿 Denis Istomin def. 🇺🇸 Reilly Opelka 6–4, 6–2.

Women's singles

 * Petra Martić def. 🇩🇪 Mona Barthel, 6–4, 6–1

Men's doubles

 * 🇬🇧 Luke Bambridge / 🇬🇧 Neal Skupski def. 🇮🇳 Leander Paes / 🇲🇽 Miguel Ángel Reyes-Varela, 6–3, 6–4

Women's doubles

 * 🇩🇪 Mona Barthel / 🇨🇿 Kristýna Plíšková def. 🇺🇸 Asia Muhammad / 🇺🇸 Maria Sanchez, 6–3, 6–2