Garbiñe Muguruza and Ons Jabeur had quick victories to reach the third round of the U.S. Open.
The ninth-seeded Muguruza, a two-time Grand Slam champion, beat Andrea Petkovic 6-4, 6-2. She could next face No. 18 seed Victoria Azarenka, who reached her third U.S. Open final last year.
The 20th-seeded Jabeur routed Maria Camila Osorio Serrano 6-0, 6-1 in 53 minutes.
Defending champion Naomi Osaka has advanced to the third round of the U.S. Open after her second-round opponent withdrew for medical reasons.
The defending champion was set to play Olga Danilovic of Serbia in the first match of the day in Arthur Ashe Stadium.
The U.S. Tennis Association said the match between women's No. 12 seed Simona Halep and Kristina Kucova would move to Ashe.