Sharapova Pulls, Clijsters Rolls at WTA Los Angeles

"I'm extremely disappointed to have to withdraw because of the re-injury of a muscle strain that I sustained late last year and which has been bothering me all week," Sharapova said in a statement. "Reaching the No. 1 ranking has been a life-long goal of mine, and achieving it here in Los Angeles would have been a dream come true. I'm eager to get back to feeling 100 percent healthy and playing as soon as possible to restart my quest to become No. 1."

With the walkover win, No. 9 seed Daniela Hantuchova receives a free pass into the semifinals.

The No. 5-seeded Clijsters looked formidable in dispatching of No. 4 seed Nadia Petrova 6-4, 6-2, setting up a semifinal meeting with No. 13 Francesca Schiavone, who beat former No. 2 Conchita Martinez 7-5, 6-4.

"The Russians play a similar type of game, they hit the ball hard and consistent -- I enjoy playing them," Clijsters said after dispatching of Petrova. "I kept her moving from side to side. I had to mix it up."

Also into the semis trying to salvage her down year is Russian No. 3 seed Elena Dementieva, who rolled past Italian qualifier Tathiana Garbin 6-1, 6-1.

Lined up for Saturday in L.A. are (9) Hantuchova vs. (3) Dementieva (Russian leads career meetings 6-2), (5) Clijsters vs. (13) Schiavone (Belgian leads 5-0), and in the doubles semis Dementieva/Pennetta vs. Spain's (2) Martinez/Ruano Pascual, and China's Li/Sun vs. Americans Haynes/Mattek.