Dominika Cibulkova has reached the Australian Open quarter-finals with a hard-fought victory over Victoria Azarenka.

Azarenka, the champion in 2012 and 2013, had been expected to prevail under the roof in the Rod Laver Arena, but it was Cibulkova who proved the stronger, eventually winning 6-2 2-6 6-3.

Cibulkova had come through a tough passage to reach the last 16, defeating Kirsten Flipkens, Tsvetana Pironkova and Alize Cornet, and she wasted little time in impressing against the two-time winner in Melbourne.

The Slovakian broke in Azarenka's opening service game, and although the 11th seed was immediately pegged back, she struck twice more as she made light work of her opponent's usual reliable delivery.

Azarenka wasn't producing the tennis that had seen her dispatch Caroline Wozniacki and Barbora Zahlavova-Strycova, but at the start of the second, she made the first move to alter the momentum of the contest by opening up a 3-1 lead.

Cibulkova quickly fell a double-break behind, and although she halved the deficit after eight games, Azarenka gave herself the edge heading into the decider by breaking for a third time in the set.

When Azarenka gained the early lead in the third, it appeared as though she would ease through to the next round but back came Cibulkova, who came through an extended third game to get back on serve.

All of a sudden, Cibulkova was in the ascendancy but she wasted opportunities to move a break in front and Azarenka held on to ensure that the score reached 3-3 as the contest entered the closing stages.

However, in the seventh game, Cibulkova finally broke Azarenka's resistance before striking again in the concluding game to book her place in the last eight.