BEIJING — Rafael Nadal moved into the quarterfinals of the China Open with a 7-6 (3), 6-4 victory over Canada's Vasek Pospisil Wednesday. The third-seeded Spaniard picked up his game considerably following his first-round victory over the 230th-ranked Chinese wild card Wu Di, during which he was broken four times. Against Pospisil, Nadal only faced one break point — and he saved it. Also Wednesday, second-seeded Tomas Berdych lost 6-4, 6-4 to Pablo Cuevas in the first round, just two days after winning his first title of the year in the rain-delayed Shenzhen final. The second-seeded Berdych, the 2011 China Open champion, will now have to wait at least another week to secure a spot in the eight-player field for the ATP Finals in London. He's currently in fifth place in the standings and has a lead of more than 300 points over his nearest competitor, Kei Nishikori. Berdych said the short turn-around after Monday's final in Shenzhen made it difficult to adjust to the conditions in Beijing. 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. Seven women have retired or withdrawn from matches this week, including top seed Simona Halep and Eugenie Bouchard.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.
