Sam Stosur dumped world No. 2 Maria Sharapova out of the Japan Open on Thursday, a straight-sets win giving the Australian a place in the semifinals.
Stosur prevailed 6-4, 7-6(10) to register only her second career win over Sharapova in 12 encounters.
The 2011 U.S. Open champion performed doggedly, saving five of eight break points compared to Sharapova's one of five, and outlasting the 25-year-old Olympic silver medalist in the second set tiebreak.
Sharapova had beaten Lucie Safarova of the Czech Republic to earn the quarterfinal berth.
For Stosur, another Russian stands in the way of a place in the final after Nadia Petrova came back from a set down to defeat Italy's Sara Errani 3-6, 7-5, 6-3 earlier Thursday.
On the other side of the draw, Poland's Agnieszka Radwanska plays Caroline Wozniacki and Angelique Kerber faces world No. 1 Victoria Azarenka.