LINZ, Austria - Wednesday wasn't a good day for the seeds of the Generali Ladies Linz but they were a perfect 4-0 on Thursday, with Petra Kvitova, Jelena Jankovic, Dominika Cibulkova and Daniela Hantuchova all reaching the quarterfinals of the $220,000 International-level tournament.

Kvitova, the No.1 seed, was the only one to win in straight sets, dispatching Austrian wildcard Patricia Mayr-Achleitner, 62 63. It wasn't as easy as the score looked for Kvitova, with five of the six games she won in the 41-minute first set going to deuce - and most of them to several deuces - but she managed the big points well, losing serve once but breaking serve five times herself.

Jankovic, the No.3 seed, lost the first set but had few problems in the rest of a 36 62 61 win over Anne Keothavong, arguably Britain's most successful player of the last 20 years, reaching six WTA semifinals and cracking the Top 50.

"My opponent played very well. She was solid off the ground and didn't give me many chances," Jankovic said. "It took me a while to find my rhythm and feel comfortable on the court, but I took control in the second set and played better and better. I'm very glad to get through this match, it really was a tough one."

The Slovaks also battled back from a set down, first No.7 seed Cibulkova, who missed out on a 5-1 first set lead and three set points but ended up coming back for a 67(1) 63 61 win over Sara Errani. At night, No.8 seed Hantuchova rallied from 75 30 down for a lengthy 57 63 64 win over Ksenia Pervak.

In the only all-unseeded match-up, Lucie Safarova got past Alberta Brianti, 64 62. Brianti had taken out No.5 seed Sabine Lisicki a day before.

The other three quarterfinal spots were determined on Wednesday, with three players out of the qualifying - Sorana Cirstea, Anastasia Rodionova and Evgeniya Rodina - all making it through to the final eight. Cirstea was a qualifier while Rodionova and Rodina were both lucky losers in the draw.

All four Generali Ladies Linz quarterfinal matches take place on Friday.