MELBOURNE, Jan. 22 (Xinhua) -- Victoria Azarenka's 18-match winning streak at the Australian Open ended in an upset 6-1, 5-7, 6-0 quarterfinal loss to Agnieszka Radwanska on Wednesday.
The first major of the season extends its prevailing tumbling of star players and dramatic ousting of reigning champions. On Tuesday, three-time reigning champion Novak Djokovic was knocked out the tournament by Stanislas Wawrinka in five-set thriller.
In the fourth round, the dominant Serena Williams and Maria Sharapova also suffered early exits.
Serbia's 14th seed Ana Ivanovic, who stunned Williams in three sets then fell victim to Canada's teenager Eugenie Bouchard.
Fifth-seeded Radwanska ended a streak of three consecutive quarterfinal defeats at the Australian Open with a stunning display of versatile shot-making that confused the big-hitting defending champion.
She next plays No. 20 Dominika Cibulkova, who won the last eight games in a one-hour, 6-3, 6-0 quarterfinal rout of No. 11-seeded Simona Halep.
Azarenka's loss leaves 2011 French Open champion Li Na as the only major winner remaining in the women's draw.
Li will play 19-year-old Canadian Eugenie Bouchard in the other semifinal.