Two-time champion Vera Zvonareva round wins, while second- seeded Dominika Cibulkova came up a loser Tuesday at the $220,000 Pattaya Open tennis tournament.

The top-seeded Zvonareva handled Thai qualifier Varatchaya Wongteanchai 6-2, 7-5 on the hardcourts at Dusit Resort Pattaya. The Russian Zvonareva captured back-to-back titles in Pattaya City in 2009 and 2010.

Up next for the former Wimbledon and U.S. Open runner-up will be Uzbekistan's Akgul Amanmuradova on Wednesday.

The third-seeded Hantuchova resumed her winning ways at this event with a 6-2, 6-0 pasting of Thai wild card Nungnadda Wannasuk. Hantuchova beat Italian Sara Errani in last year's finale here.

Hantuchova will meet Pole Urszula Radwanska in the round of 16.

Britain's Anne Keothavong dismissed Cibulkova in 6-4, 6-1 fashion, while fourth-seeded Russian Maria Kirilenko moved on with a 4-6, 7-6 (8-6), 6-3 victory over Aussie Casey Dellacqua on Day 2.

Other upsets came when qualifier Su-Wei Hsieh of Taipei humbled fifth-seeded Chinese Zheng Jie 6-3, 6-2 and Thai veteran Tamarine Tanasugarn took out sixth-seeded Kazakhstani Galina Voskoboeva, who retired while trailing 6-3, 4-2 due to a viral illness. The 34-year-old Tanasugarn was the Pattaya Open runner-up to Zvonareva two years ago and was also a finalist here way back in 1996.

Eighth-seeded American Vania King avoided the upset bug with a 6-4, 6-2 decision against Brit Heather Watson.

Additional first-round wins came for Amanmuradova, Radwanska, Russian Alla Kudryavtseva, qualifier Kai-Chen Chang of Taipei, Japan's Misaki Doi and 41- year-old Kimiko Date-Krumm, and Indian Sania Mirza, who titled here in 2009 and topped Japan's Ayumi Morita 3-6, 6-1, 6-2 on Tuesday.

The 2012 Pattaya City champion will collect $37,000.