Rome: Switzerland's Stanislas Wawrinka made an improbable comeback in the first-set tie-breaker and then dominated the action in the second set en route to a 7-6 (9-7), 6-2 victory on Friday in the Italian Open quarterfinals over Rafael Nadal.
This is Nadal's earliest exit from this clay-court event since 2008.
The Spanish seven-time champion, who brought a 12-1 record against Wawrinka into the contest at the Foro Italico, appeared to have the match under control when he led 6-2 in the first-set tie-breaker, but he proceeded to lose five straight points and eventually drop the set in a stunning turnaround.
Already struggling with his confidence in a season in which he has only reached two finals, including a lopsided loss last Sunday to Britain's Andy Murray in the Madrid Open championship match, Nadal had a difficult time bouncing back in the second set despite being urged on from the stands by American comedic actor Ben Stiller.
The Spanish No. 4 seed fell behind two breaks of serve due in part to big hitting from the baseline by his opponent and his own ability to get penetration on his ground strokes.
Nadal continued to fight, but the eighth-seeded Swiss sealed the victory in two hours and five minutes with one final forehand winner.
In Saturday's second semifinal, Wawrinka will take on second-seeded countryman Roger Federer, who cruised past Czech Tomas Berdych 6-3, 6-3 on Friday.
The first semifinal will pit Serbian top seed Novak Djokovic against Spain's David Ferrer, who advanced with quarterfinal victories over Japan's Kei Nishikori and Belgium's David Goffin, respectively.
Wawrinka, Federer and Ferrer are all seeking to capture their first Italian Open title, while Djokovic has won this key French Open tune-up event on three occasions.