CARSON, Calif. — Maria Sharapova overcame problems with her new service motion to outlast Urszula Radwanska of Poland 6-4, 7-5 in the quarterfinals of the LA Women’s Tennis Championships on Friday night.

Still finding her way after shoulder surgery that sidelined her for nearly 10 months, Sharapova is working on an abbreviated service motion to take pressure off her right shoulder.
“I made a lot more errors than I wanted to. In the second set, just kind of went off,” she said. “I created so many bad habits. Eventually it’s going to work itself into place.”
She struggled to control it in the second set, when she held serve just twice. She gained her first hold at love to tie the set at 5-all. Sharapova broke Radwanska in the next game, then served out the match.
Sharapova’s ace on her second serve set up match point. Her forehand winner in the corner was called long, but she challenged the call and won to advance to Saturday’s semifinals. Two of Sharapova’s previous three matches went three sets.
“It’s not really tired,” she said about her shoulder. “After playing four matches, it’s kind of a shock to the system. The benefit is you get in these situations and you learn from that.”
Radwanska led 5-3 in the second set, when Sharapova committed 11 of her 13 double faults. But the Pole got broken in her final two service games, pounding her racket on the hardcourt in disgust.
“Her second serve she was hitting 70 miles per hour and I was pounding on it,” said Sharapova, who stepped into the court and ripped several winners off Radwanska’s short serves.
Sharapova will play No. 10 seed Flavia Pennetta of Italy, runner-up here last year, who defeated second-seeded Vera Zvonareva of Russia 6-4, 6-2.
Sharapova has yet to win the title in Carson, where she gained the world’s No. 1 ranking during the tournament in 2005. She returned to singles play in May and came into this week ranked 61st.
“I have no regrets,” she said. “Slowly but surely I’m finding my way on the court. I feel like I’m moving better. A lot of what you lose is hand-eye coordination and I feel like I’m getting that back.”
Samantha Stosur rallied for a 4-6, 6-3, 6-4 quarterfinal victory over Zheng Jie of China, moving the Aussie doubles specialist into the semifinals for the second consecutive week.
Stosur has enjoyed a solid run in singles the last few months, reaching a career-best ranking of 18th in June. She has yet to win a singles title on the WTA Tour, although she’s been a four-time runner-up, including once last year.
“It’s definitely a goal of mine to try and win a singles title. I’ve been in four finals and lost every one of them in three sets,” she said. “My whole career I’ve been trying to become a better singles player. This year it’s all just come together.”
A week ago, Stosur defeated Serena Williams in three sets before losing to eventual winner Marion Bartoli in the semifinals at Stanford.
Stosur called the victory “one of my best wins. She’s probably the best player out here at the moment, so no doubt it gave me confidence.”
She beat then-No. 2 Dinara Safina in the quarterfinals at Miami in March and reached the French Open semis in June.
The 25-year-old Australian is best known for her doubles success, including 22 career titles, the world’s No. 1 ranking and two Grand Slam mixed titles.
Stosur scored her second win over the 14th-seeded Zheng this week, having beaten the Chinese woman in doubles on Wednesday. Stosur’s booming serve at 40-love closed out their singles match and avenged a three-set loss to Zheng at Dubai in February.
Stosur, seeded 13th, advanced to the semifinals against Sorana Cirstea of Romania, a 7-6 (4), 1-6, 7-5 winner over eighth-seeded Agnieszka Radwanska, Urszula’s sister. The Aussie will be able to concentrate fully on singles after she and partner Rennae Stubbs, the top seeds, were knocked out of doubles Thursday.
Stosur needed two hours to put away Zheng, who upset No. 1-ranked Safina in three sets in the third round Thursday. Stosur connected on 77 percent of her first serves and saved 5 of 8 break points, including the only one in the third set.
Cirstea played with pain from plantar fasciitis in her right foot that began bothering her in the tiebreaker. She was assured by a trainer that she couldn’t injure her foot any more, so she kept going.