Caroline Wozniacki was dumped out of the Rome Masters by Maria Sharapova after a bruising semi-final encounter.
The seventh-seeded Sharapova edged an enthralling first set but looked to be fading as the world number one Dane hit back to lead 3-1 in the second set.
With both struggling to hold serve, it was the Russian, 24, who produced a brutal and relentless response.
Five games in a row stunned Wozniacki and the 7-5 6-3 win set up Sunday's final with Sam Stosur, who beat Li Na.
Stosur's 7-6 (8-6) 6-0 triumph was the Australian's third straight sets win to maintain her unbeaten record against China's world number four.
After breaking in the first game and then building up a 5-3 lead, it was a surprise to see Stosur looking so rattled as she tried to wrap up the first set.
Having been taken to a tie-break after wasting set points, the Australian kept her cool to finally decimate her Chinese opponent in a one-sided second set.
On the prospect of playing for the Italian title nearly a year after being runner-up in the French Open, Stosur said: "I'm looking forward to it. I haven't played a final for a year now, it will be a very exciting day."
The second semi-final between Wozniacki and Sharapova was the contest of the day though.
Despite the service breaks by both players, it was an intriguing and pulsating encounter that lasted 1 hour 50 minutes with the Russian overcoming an opponent she had not beaten since the same tournament in 2008.
Sharapova broke the Dane's serve in the second game of the first set and seized the initiative to take it with a service hold at 7-5 after four breaks in a row.
Wozniacki, winner of three titles this year, battled back with a stunning combination of defence and the occasional forehand firework, to lead 2-0 in the second set.
The tide seemed to be turning at the end of that second game as Sharapova lay face down in the Italian clay after a crushing return from the Dane recovered a seemingly lost cause with the Russian at the net.
But despite trailing 3-1, the three-time grand slam champion simply increased her power as she reeled off five successive games to shock the 20-year-old.