Caroline Wozniacki (right) walks to a chair after her loss to Kaia Kanepi (left) at the Japan Pan Pacific Open Tennis Tournament in Tokyo on Wednesday, sept. 28, 2011.

Kaia Kanepi eliminated top-ranked Caroline Wozniacki 7-5, 1-6, 6-4 to advance to the quarterfinals of the Pan Pacific Open in Tokyo.

The 43rd-ranked Kanepi rallied from three games down in the third set and won the match when she broke the defending champion with a forehand down the line. After a sluggish start, Wozniacki dominated the second set but was unable to keep the momentum in the third when she was broken three times by the Estonian player.

"I played some good tennis in the second set and the first half of the third but then I couldn't get my serve in," Wozniacki said. "Kaia played a good match today. I'll try to do better next time."

Kanepi will face ninth-seeded Agnieszka Radwanska of Poland in the quarterfinals. Radwanska beat eighth-seeded Jelena Jankovic of Serbia 2-6, 6-4, 6-0. Also, second-seeded Maria Sharapova earned a 7-6 (4), 7-6 (4) win over 13th-seeded Julia Goerges of Germany. Sharapova came back from a 1-3 deficit in the first set and then rallied from 3-5 down in the second.

"It was a tough match," Sharapova said. "Two sets go to tiebreak, I was pleased that although I really didn't play my best in the match I stepped it up in the tiebreaks and that was the difference."

Sharapova will face fifth-seeded Petra Kvitova of the Czech Republic in a rematch of this year's Wimbledon final. Kvitova beat Vania King of the US 6-1, 7-6 (4).

"It was a tough loss against her at Wimbledon," Sharapova said. "I thought she played great tennis. She hit the ball big and deep, had a great serve. I hope I can learn from that match and I'm looking forward to it."

Maria Kirilenko of Russia also advanced, beating Ana Ivanovic 6-3, 6-1, and seventh-seeded Marion Bartoli of France defeated Peng Shuai of China 6-2, 6-1.

Kirilenko, who knocked out US Open champion Samantha Stosur on Tuesday, broke her opponent in the first game of the second set and never looked threatened by the 12th-ranked Serb, who took a medical time-out midway through the second set because of a sore back.

"To be honest, I was a little bit tired today when I woke up," Kirilenko said. "I didn't have that much time to recover because we finished so late yesterday."

Kirilenko will next face compatriot and fourth-seeded Vera Zvonareva of Russia, who defeated Iveta Benesova of the Czech Republic 6-1, 6-2.