Samantha Stosur stunned Serena Williams to set up a semi-final showdown with Jelena Jankovic.
Stosur added a second modern great to her list of French Open scalps after an epic quarter-final victory over world number one Serena Williams.
Seventh seed Stosur, who on Monday became the first woman to beat Justine Henin at Roland Garros for six years, held off a tremendous fightback by Williams - who had match point - to win 6-2 6-7 (2/7) 8-6 on Philippe Chatrier Court.
Stosur made full use of her impressive physique to overpower Williams for almost two sets but looked to have blown her chance after serving for the match in the second.
Yet, she held her nerve in a dramatic decider to win in two hours and 24 minutes.
The Australian, who lost to eventual champion Svetlana Kuznetsova in the last four last year, will now play Jelena Jankovic for a place in Saturday's final.
Stosur had already assured her place in French Open folklore by ending Henin's unbeaten run at Roland Garros.
She also had a win over Williams to her name but had been brushed aside in their last meeting at the Australian Open, the American going on to claim her 12th grand slam singles title.
After being taken to deuce in the opener, Stosur proceeded to worry Williams in every one of the top seed's first-set service games.
She had two break points in game two, took Williams to deuce two games later, before reeling off four games in a row to clinch the set as she absorbed the American's power and returned it with interest.
Her dominance looked set to continue into the second set when two Williams double faults handed her seven straight points and triple-break point.
The top seed fought back to hold and did so again after facing another break point in game four, screaming and yelling "Yes!" after successive points, but her poor technique inside the service line continued to be exposed.
Another two double faults gifted Stosur three more break points in game eight.
Williams looked close to tears after saving the second but a horrible backhand error handed Stosur the third and a chance to serve for the match.
She blew it, falling 30-40 behind, and Williams pounced to convert her only break point of the set before running away with the tie-break.
Her ninth double fault gifted Stosur the opening game of the decider but she broke right back and almost broke again in game six.
Serving to stay in the match in game 10, Stosur collapsed from 30-0 up to match point down, Williams only just long with what would have been a winning forehand.
The 13th game proved the decisive moment, and included one of the points of the tournament which Stosur eventually won after brilliant chasing from Williams.
A sumptuous backhand completed the break before the Australian held her nerve to serve it out.
Jankovic advanced to her third Roland Garros semi-final after coming through 7-5 6-4 in a topsy-turvy clash with Yaroslava Shvedova, which saw 10 breaks of serve.