BEIJING — Naomi Osaka won the final 10 games of the match and beat Alison Riske 6-4, 6-0 Thursday to reach the quarterfinals at the China Open.
The two-time Grand Slam champion from Japan served seven aces and stretched her winning streak seven matches.
“Today I was kind of happy because the first set was really tight. I was thinking that it’s been a while since I’ve kind of had to be really serious,” Osaka said. “It seemed like she was the type that would use my pace, especially on the forehand. I just tried not to give her too much.”
Osaka will next face Bianca Andreescu in a meeting of the last two U.S. Open champions. The Canadian easily defeated American qualifier Jennifer Brady 6-1, 6-3.
Osaka called Andreescu “an amazing player.”
“I feel like she’s doing better than I was last year, so it’s all cool,” Osaka said. “I have to learn from her, too.”
Defending champion Caroline Wozniacki also advanced to the quarterfinals, beating Katerina Siniakova 7-5, 6-4.
“I was trying to stay aggressive. I was trying to move the ball around a lot,” the 16th-seeded Wozniacki said. “I think I was successful most of the time, but there was a couple of games where she played good or I played a little sloppy.”
Also, Daria Kasatkina beat Ekaterina Alexandrova 6-4, 6-3.
In the men’s draw, John Isner hit 21 aces in a 7-6 (3), 7-5 victory over Dan Evans.
The American will next face Stefanos Tsitsipas in the quarterfinals. The third-seeded Greek came back from a set down to defeat defending champion Nikoloz Basilashvili 4-6, 6-3, 6-2.
“In the second and third sets, I felt really comfortable,” Tsitsipas said. “I returned well, served well and did everything well.”
Also, Alexander Zverev beat Felix Auger Aliassime 6-3, 6-1, and Sam Querrey defeated Diego Schwartzman 7-6 (2), 6-7 (6), 6-3.
Top-seeded Dominic Thiem will play Andy Murray on Friday. Murray won consecutive singles matches in Beijing for the first time since undergoing hip surgery in January.