Top seed Caroline Wozniacki had a very short quarterfinal as sixth seed Agnieszka Radwanska retired with left foot injury after 29 minutes at 5-0 down. Wozniacki was trailing by the same score against Aleksandra Wozniak last year in the second round of Tokyo and had to retire with a viral infection.
The 20-year-old Wozniacki could rise from No.2 to No.1 in the rankings for the first time if she wins the Toray Pan Pacific Open and reaches the quarterfinals of the next week’s China Open in Beijing.
The Dane's opponent in the semifinals will be No.8 seed Victoria Azarenka, who ended the successful run of qualifier Coco Vandeweghe 6-2 6-1.
The other semifinal pair includes fifth seed Francesca Schiavone and seventh seed Elena Dementieva. The Italian defeated Kaia Kanepi 7-5 4-6 7-5 in the quarters, the Russian beat compatriot and No.2 seed Vera Zvonareva 7-5 6-2. (photo: Ralf Reinecke)