Ninth-seeded Jelena Jankovic advanced to the round of 16 by routing Johanna Larsson 6-1, 6-0. The 96th-ranked Larsson had upset Sloane Stephens in the second round.
Meanwhile, Peng Shuai beat another seeded player at the U.S. Open to reach her second straight Grand Slam round of 16.
Two days after upsetting fourth-seeded Agnieszka Radwanska, Peng defeated 28th-seeded Roberta Vinci 6-4, 6-3 on Friday. The Chinese veteran had gone two years without making it past the second round at a major tournament before her Wimbledon run this summer. However, she didn't meet any seeded players in the first three rounds there before losing to eventual champion Petra Kvitova in straight sets.
Peng, ranked 39th, will face 14th-seeded Lucie Safarova or 22nd-seeded Alize Cornet to try to reach her first Grand Slam quarterfinal.