Kvitova ousts former champion Keys at rainy Western and Southern Open
Fifth seed Elise Mertens, former world No 1 Angelique Kerber and American Jennifer Brady were among those who also advanced on Monday
Two-time Wimbledon champion Petra Kvitova was among the seeded women to take the court at the Western and Southern Open on Monday and came away victorious against a former champion in Cincinnati.
The Czech saved eight of nine break points against her serve while breaking Keys three times, and that was enough to pull out the victory. Kvitova’s countrywoman Barbora Krejcikova, the ninth seed, made her singles debut at the WTA 1000 event with a 6-3, 6-2 win over Daria Kasatkina.
Fifth seed Elise Mertens and American Jennifer Brady also advance
Fifteenth seed Elise Mertens also was a straight-sets winner, taking down Nadia Podoroska 6-3, 6-4, while 13th seed Jennifer Brady defeated Ekaterina Alexandrova 6-3, 7-6 (7-3) in a match that finished shortly before 1 AM local time.
The field in Cincinnati includes nine of the top 10 players in the rankings, led by Ashleigh Barty and Naomi Osaka in their first appearances since the Tokyo Olympics.
In other matches on the first day of play, Heather Watson defeated Aliaksandra Sasnovich 6-2, 3-6, 6-1, while Paula Badosa outlasted Petra Martic 4-6, 6-4, 7-6 (11-9) in a two-hour, 34-minute marathon.
Former world No 1 Kerber scores straight-sets win over Sakkari
In other first-round matches, former world No 1 Angelique Kerber defeated Maria Sakkari 6-2, 6-2 while American Alison Riske defeated young Canadian Leylah Fernandez by the same score line.
Also on Monday, Yulia Putintseva breezed past Zhang Shuai 6-2, 6-0, Jelena Ostapenko beat Tamara Zidansek 7-5, 6-1 and Jil Teichmann defeated Sorana Cirstea 6-2, 6-0.
American Danielle Collins, who won back-to-back titles in Palermo and San Jose as part of a 12-match winning streak, lost her second match in a row. Collins, who lost in the round of 16 last week in Montreal, had to retire with an injury as she trailed countrywoman Shelby Rogers 6-4, 2-1.