Wozniacki had lost three consecutive matches heading into the Japan Open but has been sharp this week, as shown in a 6-4, 6-1 win over Tamarine Tanasugarn. Wozniacki took 63 percent of the points in the second set in advancing to the semifinals for the fourth time this year.

She will meet Jarmila Gajdosova, against whom she is 1-0 in WTA matches, in the semis. Gajdosova was a 7-5, 7-5 winner over Klara Zakopalova in her quarterfinal match..

The other semifinal Saturday sends fifth-seeded Kaia Kanepi against No. 8-seeded Aleksandra Wozniak. Kanepi took a 7-6 (7-4), 7-6 (7-1) decision from Anastasia Pavlyuchenkova on Friday and Wozniak eliminated Samantha Stosur 7-5, 6-3. Kanepi is 1-0 in her career against Wozniak.

Saturday's semifinal winners are to play Sunday with the 2008 Japan Open champion's share of $28,000 at stake.