$ 0 0 Third seed Maria Sharapova was knocked out of the AustralianOpen by Slovak Dominika Cibulkova on Monday, the second major upset in as many days. The Russian, who took a medical timeout between the second and third sets, crashed 3-6, 6-4, 6-1 against the 20th seed in the fourth round to follow Serena Williams out of the tournament. Cibulkova had never been beyond the fourth round in six previous attempts in Melbourne, although she has made the last eight at all the other three Grand Slams. Her shock win set up a quarterfinal encounter with either eighth-seeded Serb Jelena Jankovic or Romanian Simona Halep, seeded 11. "I was 100 percent sure I could win. I never doubted myself even when I lost the first set," she said. "I knew what I needed to do. The most important thing is to believe in yourself." It was an error-strewn and see-sawing match in which Cibulkova won five straight games in the second set and then lost the next four. After racing through the first set Sharapova, who has reached eight major finals and won four, with her last success coming at the French Open in 2012, appeared to have a problem with her left buttock.