MELBOURNE, Australia -- Victoria Azarenka's run as Australian Open champion ended in a yelling, screaming quarterfinal defeat to Agnieszka Radwanska on Wednesday, continuing the flow of stars tumbling out of the season's first major.
Fifth-seeded Radwanska stopped Azarenka's 18-match winning run at Melbourne Park and her own streak of three consecutive quarterfinal defeats at the Australian Open, winning 6-1, 5-7, 6-0 with a stunning display of versatility and court craft that shocked and confused the two-time champion.
The result means both defending champions were out in the quarterfinals -- Novak Djokovic lost in five sets to Stan Wawrinka on Tuesday night.
With the three biggest stars of the women's game falling one by one -- top-seeded Serena Williams, followed by Maria Sharapova and two-time Australian Open champion Victoria Azarenka -- the door has opened for a first-time winner at Melbourne Park.
Only fourth-seeded Li Na has won a Grand Slam before -- the 2011 French Open.
Li, a two-time finalist in Australia, will play 19-year-old Canadian Eugenie Bouchard in the other semifinal.
Radwanska played drop shots and slices from the baseline, forcing Azarenka to come forward and then lobbing or passing her. She hit touch volleys with calm precision, and instinctively anticipated Azarenka's shots.
She didn't fall into big-swinging rallies against the second-seeded Azarenka, either, continually mixing it up and saving the power for when she needed it.
"She was aggressive. She was making everything. She was guessing right," Azarenka said. "I was just playing a little bit too predictably.
"In the second set I managed to fight back. Third set, the first game was important. I let it go, like easily let it go. From there just couldn't get back to it."
Radwanska was also safe on her own serve, dropping just two games in the two-hour match while breaking Azarenka six times. She hadn't beaten Azarenka in their last seven matches, and had only won three of their previous 13.
"I said to myself one day I have to have one step forward and do the semifinal, and I'm so, so happy that I did it finally," Radwanska said of her first run to the semis of a major on hard courts. She reached the final at Wimbledon in 2012, becoming the first player from Poland to reach a major final in the Open Era, and the semifinals last year.
"I really had nothing to lose. She was defending the title, not me. I was really trying to play my best tennis, go for every shot I could," Radwanska said.
Azarenka went down in a flurry of unforced errors, making 47 in three sets as she tried to push Radwanska around.
She seemed to have momentum at the end of the second set, when she leveled after breaking in the last game. But she didn't carry it through, pushing a forehand fractionally too wide on the first point and unsuccessfully challenging the out call.
It was a sign of things to come. She won only 14 points in the third set, and was broken three times.