Paris, France (Sports Network) - Dominika Cibulkova is through to the quarterfinals after taking down top-seeded Victoria Azarenka on Sunday at the French Open.

The 15th-seeded Cibulkova defeated Azarenka of Belarus 6-2, 7-6 (7-4) to advance to the quarterfinals at Roland Garros for the first time since 2009, when she made it to the semifinals.

The Slovak recorded 31 winners, compared to 19 for Azarenka, and improved to 3-6 in her career against world No. 1s. Cibulkova came into the match with an 0-3 mark against top 10 opponents this year.

"I have never been in the Top 10, but I find it easier to play against them," Cibulkova said. "I'm showing all the time my game is good enough to be there and hopefully this year I'll make it. This tournament I'm playing well against everyone and I think I'm getting more mature and more tough mentally."

The Australian Open champion Azarenka was a perfect 10-0 in Grand Slam play this year, including her first-ever major title in Melbourne back in January.

Azarenka wasn't so happy about the result.

"I don't know how to describe my performance today. It wasn't satisfying at all, and I can't even find a positive about it," she said. "But it happens. It has been too little time since the match. Maybe in a few hours I'll find something I can be happy with about all of this.

"I'm just going to go on the practice court, practice again and improve."

Cibulkova will next take on 2010 runner-up Samantha Stosur, who beat American Sloane Stephens 7-5, 6-4.

German Angelique Kerber and Italian Sara Errani also posted fourth-round victories on Day 8.

The 21st-seeded Errani started the day by taking out 2009 champion Svetlana Kuznetsova 6-0, 7-5 on Court Philippe Chatrier.

The win for Errani came just two days after she beat 2008 winner Ana Ivanovic in the third round.

The 25-year-old Italian has won three titles this year. She won in Acapulco, Barcelona and Budapest -- all on clay -- after a quarterfinal loss to Wimbledon champion Petra Kvitova at the Australian Open in January, which marked her best finish in 18 Grand Slam events.

Kuznetsova, the No. 26 seed, came into the match with a 5-0 career mark against Errani, who will next do battle with Kerber.

Kerber, the No. 10 seed, defeated Croat Petra Martic 6-3, 7-5 to secure her spot in the quarters.

Errani and Kerber had never made it past the second round here coming into this year's event.

Fourth-round play will continue Monday with defending champion Li Na of China and second-seeded Maria Sharapova in action.

Li will take on Yaroslava Shvedova, while Sharapova will battle Klara Zakopalova. Also, reigning Wimbledon winner Petra Kvitova will meet Varvara Lepchenko and 23rd-seeded Kaia Kanepi will square off against Arantxa Rus.

06/03 15:47:23 ET