Henin blasts Zvonareva, Hantuchova upset at Zurich Open

Besides Henin and Kuznetsova, France's Marion Bartoli -- who was made the ninth seed when No. 4 Maria Sharapova withdrew on Sunday -- is the only other seed remaining in the draw.

Early in Kunzentsova's match, Henin and Bartoli appeared to be the only seeds who would reach the final eight.

Like Henin, Kuznetsova also was playing her first match and struggled to find her rhythm. The Russian was immediately broken at love on her first serve and also lost her second.

The second set was a series of breaks, with Bammer holding only once while Kuznetsova was able to manage one better.

In the final set, the Russian squandered two break points at 4-3 but made up for it two games later, converting her second match point and sealing the win with a powerful cross court backhand after almost two hours of play.

"I was pretty upset with my game today. I was playing against myself," said Kuznetsova, who has won at least one match in every tournament this season except in Sydney to start the year when she retired. "It was a matter of time. If I played as hard as I can, then I knew I could play till the end.

"I might have won, but I have to play better. I have to be more concentrated."

The quarterfinals, Kuznetsova will play Italy's Francesca Schiavone, who defeated local favorite Patty Schnyder 2-6, 6-3, 6-4.