Local favourite Jo-Wilfried Tsonga overpowered world number three Novak Djokovic 6-4, 7-6 to book his place in the Marseille Open final on Saturday.
World number 12 Tsonga, who has now won his last four matches against Djokovic since losing to the Serb in the Australian Open final in 2008, will face Michael Llodra in an all-French final after the Parisian beat compatriot Gilles Simon 7-6, 6-2 in the other semi-final.
Tsonga, seeded fourth, converted his only break point in the seventh game and opened up a 5-3 lead, only for top seeded Djokovic to go 0-40 up on the Frenchman's serve in the 10th game.
Tsonga, however, fired five punishing serves in a row to snatch the opening set in 34 minutes.
Djokovic staved off two break points in the seventh game as the second set went with serve.
Tsonga, who won the South African Open earlier this month, moved up another gear in the resulting tiebreak, which he won 7-1 with a series of devastating forehands to wrap up victory after 85 minutes.
"I told myself I had to go for it," Tsonga said in a courtside interview.
"I have played an extraordinary match. I have been heroic on every important point. I am proud of having played such a match."
Djokovic admitted Tsonga had been the strongest man on the court.
"There is no reason for me to be depressed. It may be the fourth time he has beaten me, our encounters have always been tight, even in the Australian Open final," he said.
"If he does not get injured, he will reach the top five. He has an incredible self-confidence, as we witnessed on that game at 5-4 in the first set. In the final, whoever his opponent, he will be the favourite."
Tsonga's opponent will be unseeded Frenchman Llodra, whose attacking game eventually wore out second seed Simon.
Llodra saved two break points before claiming the opening set by winning the tiebreak 7-5.
He then strolled to victory with breaks in the third and fifth games of the second set, sealing victory on his first match point after 76 minutes.
"In the first set, when I had these break points against me, I focused on my first serve. I played well on the important points," Llodra said in a courtside interview.