Serena, Victoria Azarenka move on

WIMBLEDON, England -- Serena Williams, the reigning Wimbledon champion who seeks her first Olympic singles medal, advanced by beating former No. 1 Caroline Wozniacki of Denmark, 6-0, 6-3. Williams' opponent in the semifinals Friday will be top-seeded Victoria Azarenka of Belarus, who lost when they met in the Wimbledon semifinals last month.

Serena and her sister Venus, seeking their third gold medal in doubles, reached the semifinals by beating No. 2-seeded Sara Errani and Roberta Vinci of Italy, 6-1, 6-1.

Against the No. 8-seeded Wozniacki, Williams swept the first seven games. As a complement to her booming serve and slingshot returns, Williams kept one point going with a desperation, off-balance left-handed forehand.

"I haven't practiced it in a couple of months," she said. "I wish I could have hit it better."

Williams lost that exchange but won most of the other rallies. She dropped only nine points on her serve, never faced a break point and hit 30 winners to seven for Wozniacki.

"I felt a little off today, believe it or not," Williams said. "But I'm really, really hard to please."

No. 3 Maria Sharapova won a matchup of first-time Olympians, beating Kim Clijsters 6-2, 7-5. Sharapova's opponent Friday will be fellow Russian Maria Kirilenko, who defeated No. 6 Petra Kvitova of Germany 7-6 (3), 6-3.

Azarenka beat No. 7 Angelique Kerber of Germany 6-4, 7-5 under Wimbledon's roof. Kerber eliminated Venus Williams on Wednesday, but Azarenka feasted on the left-hander's serve, winning more than half of those points and breaking six times.

Information from The Associated Press was used in this report.