MELBOURNE, Australia — Serena Williams is out of the Australian Open after losing her quarterfinal match 3-6, 7-5, 6-4 to 19-year-old American Sloane Stephens.
Williams hurt her lower back while attempting to pull up short of the net during the eighth game of the second set. She called for a trainer after the ninth game with the score 5-4 and on serve.
Stephens won the second set when Williams, serving slower than usual, was broken. Williams also had her service broken in the final game of the match. She said her back bothered her, but credited Stephens.
At 2-1 and on the way to a changeover in the third set, Williams smashed her racket on the court then threw it toward her chair.
Stephens next will face defending champion Victoria Azarenka, who overcame early jitters to beat Svetlana Kuznetsova 7-5, 6-1.
After dropping serve in a fourth game that went to deuce 10 times, Azarenka dominated the rest of the match against Kuznetsova, a two-time major winner who went in ranked No. 75 as she recovers from a knee injury.
Azarenka's American rapper friend, Redfoo, returned from a concert in Malaysia to attend the match. Wearing a red sleeveless T-shirt that read "Keep Calm and Bring Out the Bottles," the name of his next single, Redfoo stood, clapped and yelled "Come on, Vika!" during the tight first set.
In the men's quarterfinals, 17-time major winner Roger Federer was playing No. 7 Jo-Wilfried Tsonga in a night match and U.S. Open champion Andy Murray was to meet Jeremy Chardy of France.
Novak Djokovic is already through the semifinals after his 6-1, 4-6, 6-1, 6-4 win over fifth-seeded Tomas Berdych on Tuesday. He'll meet No. 4-seeded David Ferrer, who survived a battle with fellow Spaniard Nicolas Almagro, 4-6, 4-6, 7-5, 7-6 (7-4), 6-2.