BEIJING (AP) -- Top-ranked Victoria Azarenka and No. 2 Maria Sharapova reached the China Open quarterfinals Thursday with straight-set wins.
Azarenka beat Elena Vesnina of Russia 6-3, 6-3, while Sharapova defeated Slovenian qualifier Polona Hercog 6-0, 6-2.
Azarenka will face Romina Oprandi of Switzerland, while Sharapova will play Angelique Kerber of Germany. Kerber beat former No. 1 Caroline Wozniacki 6-1, 2-6, 6-4.
"I played really well in the beginning and got a little tense in the second set,'' Sharapova said. "But I felt like I really needed that challenge.''
Azarenka looks to rebound from her trip last week to Tokyo, when she withdrew from the tournament after a bout of dizziness in the third round.
Li Na beat Shuai Peng 4-6, 6-2, 7-6 (3) in an all-Chinese clash. Li will face third-ranked Agnieszka Radwanska.
In men's singles, Sam Querrey of the U.S. defeated Andreas Seppi 6-1, 6-4. He'll face Feliciano Lopez, who topped Yen-hsun Lu 6-3, 7-6 (7). Mikhail Youzhny of Russia defeated Kevin Anderson of South Africa 6-3, 6-3.
Local wild card Zhang Ze upset fifth-seeded Richard Gasquet of France 6-4, 3-6, 6-4. Zhang, China's highest ranked player at 165th, has reached his first quarterfinals.
Gasquet won the Bangkok title last week.