Ostapenko, the 2017 French Open champion and a semifinalist at Wimbledon last month, has struggled mightily with her serve through two matches. She has 26 double faults so far and has needed the maximum six sets to reach the third round.
In the third round, Ostapenko will face the winner of Thursday night’s match between Maria Sharapova and Sorana Cirstea.
In other women’s matches, No. 14 Madison Keys, a finalist here last year, defeated Bernarda Pera, 6-4, 6-1 and will next play Aleksandra Krunic.
Federer books his spot in the third round
Second-seeded Roger Federer set up a third-round clash with Nick Kyrgios (more on him later) with a 7-5, 6-4, 6-4 victory over Benoît Paire. Paire, a demonstrative Frenchman, had a couple of match points against Federer this summer in Halle, Germany, but was far from a victory Thursday.
Other men’s winners on Thursday included No. 4 Alexander Zverev and No. 13 Diego Schwartzman. No 14 Fabio Fognini lost to John Millman, and…