MOSCOW, August 8 (RIA Novosti) - Former world No. one Maria Sharapova beat eighth-seed Urszula Radwanska 6:4, 7:5 in the quarterfinals of the Los Angeles Championships to secure a place in the last four.

Unseeded Sharapova, who is still trying to regain her championship-winning form after shoulder surgery in October, will now face Italy's Flavia Pennetta in the semifinal on Saturday.

Pennetta, seeded tenth, dumped Russia's Vera Zvonareva in the quarters 6:4, 6:2.

In a post-match interview Sharapova, who is working on a new serve, was cited by the Los Angeles Times as saying, "I made a lot more errors than I wanted to."

With 11 double faults Sharapova, currently ranked 60th in the world, said she experienced real problems with her serve.

"In the second set, my arm was kind of lagging behind and instead of going up, I got into a little bad habit I created," she said.