The two-time defending champion won the first four games
before Wannasuk shook off the nerves and held serve for the first time.
Zvonareva reeled off the next two games to take the
opening set, and then took a 5-1 lead in the second before Wannasuk battled
back to level it at 5-5.
Zvonareva regained her concentration to take a 6-5 lead
and the 21-year-old Wannasuk double-faulted twice in the final game for the No.
3-ranked Russian to complete the win in 76 minutes.
“When she started making her shots, I didn't play my game
anymore,” an unhappy Zvonareva said. “I just pushed the ball back and let her
play the way she wanted to play.
“That's not how I wanted to approach this match, I just
want to play my game. I should have played better and changed the pace.”
Zvonareva will play Peng Shuai of China in Friday's quarterfinals.
Fourth-seeded Daniela Hantuchova booked her spot in the
last eight with a hard-fought 7-6 (3), 6-3 win over 40-year-old Japanese player
Kimiko Date Krumm.
“It was a great game,” Hantuchova said. “She's been
fighting for every point. A lot of young girls could take a lot from her. It's
tough at that age to keep fit. I really do admire her.” Hantuchova will face
Akgul Amanmuradova of Uzbekistan, who beat Chanelle Scheepers 6-2, 6-4.
