Paris - Austrian journeyman Jurgen Melzer fought back from two sets down to beat third seed Novak Djokovic 3-6, 2-6, 6-2, 7-6 (7/3), 6-4 on Wednesday and set-up a French Open semi-final against Rafael Nadal.
After dropping the first two sets, the 29-year-old Melzer was also a break down in the third before he staged a spectacular recovery to become the first Austrian to reach the last four since former winner Thomas Muster in 1995.
The 22nd seeded Melzer has made his staggering breakthrough at his 32nd Grand Slam, having never got beyond the third round of a major before.
After cruising through the first two sets, Djokovic's brittle temperament came back to haunt him and in a tense final set he was broken in the ninth game when he dumped a backhand volley into the net.
Incredibly it was the 24th break point he had faced in the 4hr 17min match.
In the next game, Melzer wasted a match point when he netted a simple forehand volley with the entire court at his mercy and then another as he scrambled to reach a Djokovic drive.
But he bravely held his nerve to clinch a famous triumph when Djokovic went long with a forehand.
"It's the most incredible moment of my career," said Melzer, the oldest man left in the competition and who had never previously come back after losing the first two sets.
The 23-year-old Djokovic, who made the last four in 2007 and 2008, losing to Nadal on both occasions, dominated the first two sets.
He broke in the eighth game on his way to securing the first set and repeated the trick in the third and seventh games of the second.
By this stage Melzer looked on course for a routine defeat as he wilted under the Djokovic barrage.
The world number three was then 2-0 ahead in the third set and seemingly cruising before left-handed Melzer rallied in spectacular style.
After squandering six earlier break points, Melzer finally broke through to level the set at 2-2 and then raced through the next four games to snatch the set from Djokovic whose grip on the match was suddenly loosened.
In a marathon eighth game of the fourth set, a weary-looking Djokovic fought off seven break points before Melzer served two successive love games to lead 6-5 and ratchet up the pressure.
The Serbian held on with a sweet, running backhand taking the enthralling set into tiebreak.
Melzer raced to a 6-0 lead in the breaker. Djokovic saved three set points but a misguided backhand gave the gallant Austrian the fourth set which had taken 71 minutes to complete and sent the clash into its dramatic finale.