Russia's Vera Zvonareva overcame a nightmare start in her Pan Pacific Open semifinal Friday, recovering strongly to power past Wimbledon champion Petra Kvitova in straight sets. Zvonareva, struggling with her serve, trailed 0-4 to her Czech opponent in the first set before battling back to win a tie-break then romping through the second set without losing a game to seal a 7-6 (7-2), 6-0 victory. In the final Saturday, Zvonareva will take on Agnieszka Radwanska of Poland, who defeated Victoria Azarenka of Belarus 6-3, 4-6, 6-2. The 27-year-old Zvonareva, who hit a total of seven double faults in the first set, used an array of deep returns to attack Kvitova's backhand side as she fought back. “I don't even remember that I was 5-1 down in the first set. I wasn't really thinking about it at all. I was trying to find my rhythm and I couldn't find it in the beginning,” said Zvonareva, ranked No. 4 in the world. “She was playing really well. But slowly I got into the match and started making the shots I usually make and was able to turn it around. “I think I played consistent in the second set and Petra made a few mistakes. We had tough games but I was able to convert all my chances and that's why the scoreline looked like that,” she added. The 21-year-old Kvitova, ranked sixth, squandered three set points in the first set, allowing the Russian back into the match. After finding her rhythm, Zvonareva raced into a 4-1 lead in the tie-break, taking the set when Kvitova hit an easy forehand volley into the net. The Russian had to fend off five break points at the beginning of the second set but she was never really in danger. “I didn't play my game, I didn't play harder, and I played badly. She came back and played better than me and she was the first who was going for a winner. The first set should have been mine, for sure,” Kvitova said. Radwanska closed out her match against third-ranked Azarenka on her fourth match point. Serena, Sharapova out Serena Williams and Maria Sharapova have withdrawn from the China Open women's event that starts Saturday. The men's competition in Beijing also suffered a major setback earlier this week when world No. 1 Novak Djokovic pulled out with a back injury. World No. 2 Sharapova twisted her ankle against Wimbledon champion Petra Kvitova in the Pan-Pacific Open quarterfinals Thursday and was forced to quit the Tokyo tournament.