Poland's Agnieszka Radwanksa defeated Slovakia's Dominika Cibulkova 6-3, 6-4 Wednesday to book her spot in the quarterfinals of the Toray Pan Pacific Open in Tokyo.

The second seed and 2012 finalist, who is fresh off winning a title last week in Seoul, was too solid for her Slovakian opponent and needed just an hour and 20 minutes to advance.

Next up for Radwanska will be fifth-seeded German Angelique Kerber, a 6-4, 6-2 winner over Serbian Ana Ivanovic.

In other results Wednesday, Denmark's Caroline Wozniacki, the No. 4 seed, routed Slovakian Magdalena Rybarikova 6-1, 6-1 to set up a quarterfinal match versus Czech Lucie Safarova, who upset 12th-seeded Australian Samantha Stosur 6-4, 6-4.

American Venus Williams, meanwhile, followed up her upset of top seed Victoria Azarenka of Belarus by rallying to edge Romania's Simona Halep 4-6, 7-5, 6-3.

She will next take on Canada's Eugenie Bouchard, a 7-5, 6-2 winner over Serbia's Jelena Jankovic.

The third-round matches pitting Czech Petra Kvitova against American teenager Madison Keys and Russian Svetlana Kuznetsova against Romania's Sorana Cirstea were postponed by rain and will be played on Thursday.

The winners of those two matches will square off in the quarterfinals late Thursday afternoon.

The Toray Pan Pacific Open is one of the biggest events on the WTA calendar. EFE