Frenchman Jo-Wilfried Tsonga staged a spectacular third set comeback to stun world number one Roger Federer [Images] 7-6, 1-6, 7-6 on Friday and reach the semi-finals of the Montreal Masters.

Tsonga, whose looks are often compared to Muhammad Ali's, had appeared out for the count when Federer raced into a 5-1 lead in the third set.

But the seventh-ranked Frenchman lifted himself off the canvas and staggered the 15-times grand slam winner by sweeping through the next five games to force a tiebreak.

Tsonga then delivered the knockout punch by winning the tiebreak 7-3 in front of a shocked capacity centre court crowd.

The loss snapped Federer's 21-match winning streak. His last defeat was on May 2 in the semi-finals of the Masters Series event in Rome where he fell to Novak Djokovic [Images].

"It happens in tennis, it's never over until it's over and it showed today," Federer told reporters. "I think I should have won the first and he completely lost his game for an hour there.

"That's what Jo does. He doesn't make a return for three hours, then he puts in a few and then all of a sudden he's back in the match.

"I never should have allowed it but it did happen.

Tsonga said: "I don't know how I did it... I just said to myself, you have to put the ball back one more time than him and I did it. It was just amazing to change this match."

RUSTY FEDERER

Federer, playing his first event since lifting a record 15th grand slam at Wimbledon [Images] and the birth of his twins, stepped onto a sun-baked centre court expecting a battle from the big-hitting Frenchman and was not disappointed.

Tsonga, winner of two hardcourt titles already this season, was on the attack from the start testing the rusty Swiss, who is still searching for his best form and was rewarded for his initiative by taking the first set in a tiebreak 7-5.

But battling Federer flashed his pedigree in the second breaking Tsonga at the first opportunity to take a 3-0 lead.

Tsonga would finally hold serve at 3-1 but did little to slow a surging Federer, who responded by reeling off seven straight games to take the second set and a commanding 4-0 lead in the third.

Federer increased his advantage to 5-1 before the 24-year-old Frenchman suddenly rediscovered his touch.

"It's not something I go through very often being up 5-1 and ending up losing," said Federer. "All in all, I thought it was a decent match.

"I didn't think it was bad but it wasn't great either.

"It's one of those matches I can live with."

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