- World number one Caroline Wozniacki has been beaten in the Pan Pacific Open in Tokyo
- The defending champion lost 7-5 1-6 6-4 to unseeded Estonian Kaia Kanepi
- Petra Kvitova and Maria Sharapova face each other in a repeat of the Wimbledon final
World number one and defending champion Caroline Wozniacki is out of the Pan Pacific Open in Tokyo, beaten in three sets by unseeded Estonian Kaia Kanepi, ranked 43rd in the world.
Wozniacki, 21, slumped to a 7-5 1-6 6-4 defeat in her first tournament since losing to Serena Williams in the semifinals of the U.S. Open.
The Dane told reporters: "I felt I played some good tennis in the second set -- and for half of the third set. But I just couldn't get my first serves in.
"Kaia has been in the top 20 before but she had some problems with injury, that is why her ranking has dropped a little bit."
Kanepi, who was celebrating her first-ever victory over Wozniacki, added: "I'm very happy, not because I beat Caroline, but also because I played well and I hung in there."
In other matches on Wednesday, there will be a repeat of the Wimbledon final between Petra Kvitova and Maria Sharapova after both players reached the quarterfinals.
Wimbledon champion Kvitova secured a 6-1 7-6 victory over American Vania King while Sharapova took over two hours to edge past Germany's Julia Goerges 7-6 7-6.
Sharapova told reporters: "I hope I can learn from that Wimbledon final and raise my level. No matter how good she plays. I'm looking forward to it."
Other players to progress were Maria Kirilenko, who continued the form she showed in defeating U.S. Open champion Samantha Stosur, this time brushing aside Ana Ivanovic 6-3 6-1.
Also into the last eight is fourth seed Vera Zvonareva, who crushed Czech Iveta Benesova 6-1 6-2, and seventh seed Marion Bartoli, who cruised past China's Peng Shuai 6-2 6-1.