In the women’s draw, Agnieszka Radwanska of Poland, the fourth seed, advanced to the quarterfinals when Madison Keys retired from their third-round match with a thigh injury. The American lost the firs set 6-3 before calling it quits.
”This is not the way that I wanted to end up that match,” Radwanska said. ”But as we all know the year is ending soon and we can see a couple of retirements.”
Seven women have retired or withdrawn from matches this week, including top seed Simona Halep and Eugenie Bouchard. Defending champion Maria Sharapova and Serena Williams also decided to skip the tournament, citing injuries.
Germany’s Angelique Kerber moved a step closer to qualifying for the WTA Finals with a dominant 6-2, 6-3 win over Caroline Wozniacki of Denmark. Kerber, who has won four titles this season, can qualify if she reaches the China Open final.
Wozniacki’s loss means she is out of contention for the eight-woman field in Singapore.
Timea Bacsinszky of Switzerland overcame five double faults to upset seventh-seeded Carla Suarez Navarro 6-4, 4-6, 7-5 to reach the quarterfinals in a nearly 2 1/2 hour match, and Sara Errani of Italy advanced with a 3-6, 6-3, 6-2 win over Germany’s Andrea Petkovic.