MELBOURNE, Jan. 20 (Xinhua) -- Slovakia's Dominika Cubulkova knocked out third seed Maria Sharapova in the fourth round of the Australian Open here on Monday.

The 20th-seeded Cibulkova won 3-6, 6-4, 6-1 in two hours and 12 minutes.

Sharapova's defeat came less than 24 hours after top seed Serena Williams went down to Ana Ivanovic.

Though winning the first set, the Russian struggled with her serve from the eighth game, when she was broken at love while trying to serve out the set.

Sharapova quickly went 0-5 down in the second. She rallied to win four straight games, only for Cibulkova to serve the set out at the third time of trying.

The Slovakian then dominated the decider, setting up a quarterfinal against No.11 seed Simona Halep from Romania, who reached her career-first last eight at a Grand Slam tournament with victory over former world No.1 Jelena Jankovic.

The absence of Williams and Sharapova opens the door for two-time defending champion Victoria Azarenka and two-time runner-up Li Na.