Slovakia's Dominika Cibulkova produced one of the best performances of her career to dump world number one Victoria Azarenka out of the French Open in the fourth round.

Azarenka, the top seed from Belarus, had survived a scare in the first round on Monday when unheralded Italian Alberta Brianti pushed her all the way.

But there was no let-off on Sunday as 15th seed Cibulkova clinically completed a 6-2 7-6 (7/4) triumph in one hour 47 minutes.

Cibulkova raced through the first set on Court Suzanne Lenglen and looked to be cruising into the last eight when she established a 4-2 lead in the second.

Azarenka responded well, though, and two breaks of serve saw her turn the second set on its head. She soon led 6-5 and found herself serving to level things up at one set all.

However, Cibulkova was not about to let the Australian Open champion have it all her own way. The 23-year-old wasted no time asserting her authority in the tie-break and swiftly earned three match points.

Azarenka saved the first after an entertaining rally, but Cibulkova held her nerve and sealed a brilliant victory in style with a superb backhand crosscourt winner.

The Belarusian said: "I don't know how to describe my performance really today. It wasn't satisfying at all. It wasn't satisfying being out there playing that way.

"But I guess it happens. I don't know even what to find positive in my performance today. Maybe in a few hours I'll find something that I can be happy with."

Cibulkova will face either American Sloane Stephens or Australia's Samantha Stosur - the 2010 runner-up at Roland Garros and reigning US Open champion - in the quarter-finals.