Defending champion Daniela Hantuchova won through the the quarter-finals of the PTT Pattaya Open in Thailand with a straight-sets win over Urszula Radwanska.

Hantuchova won 6-3 6-2 to book a last-eight meeting with eighth-seeded American Vania King, who easily beat Alla Kudryavtseva 6-1 6-3.

Qualifier Su-wei Hsieh continued her impressive run as she toppled Japanese veteran Kimiko Date-Krumm 7-5 6-0.

The world 159 will next meet Sania Mirza after she upset Anne Keothovong, who had knocked out second seed Dominika Cibulkova in the first round, 6-4 7-5.

The other quarter-final matches will see top seed Vera Zvonareva meet Sorana Cirstea while local hopeful Tamarine Tanasugarn faces fourth seed Maria Kirilenko.