(CNN) -- Australian Sam Stosur continued her giant-killing habit at the French Open by beating top seed Serena Williams to book a place in the final four.
Stosur, who eased past four-time champion Justine Henin in the previous round, triumphed 6-2 6-7 8-6 in two hours and 24 minutes at Roland Garros.
The seventh seed will play Jelena Jankovic in the semifinal after the Serb beat Yaroslava Shvedova, from Kazakhstan, 7-5 6-4.
It means there will be a brand new Grand Slam winner by the end of the week, with none of the final four yet to break their duck at the major championships.
The match went with serve in the opening set until Stosur won five games in a row with some scintillating tennis, to clinch the first 6-2.
Stosur continued strongly in the second to go 5-3 up before Williams rallied and leveled at 5-5. The top seed went on to take it on a tie-break.
In a tense deciding set breaks were exchanged early on before Williams edged ahead to lead 5-4. Stosur held her nerve to survive a match point and go on to take the game.
With the match locked at 6-6 Stosur rediscovered her blistering form, and fired two winners past Williams to secure a crucial break of serve.
Stosur needed no second invitation to wrap up the match on her serve and seal a place in the last four.
"It's two great matches back-to-back for me, which is fantastic," Stosur told reporters. "It's not over yet. Now I'm in the semis and I want to definitely try and keep going. I made it to this point last year. If I can try and go another set further, then that would be great."
She will meet Jelena Jankovic after the Serb made light work of the unseeded Yaroslava Shvedova. The other semifinal sees Italian Francesca Schiavone face Elena Dementieva.