Top seed Roger Federer of Switzerland will play triple defending champion Rafael Nadal of Spain in the French Open final on Sunday, the third straight year the pair have met for the title.

In Friday's semi-finals, Federer won through with an unconvincing 6-2, 5-7, 6-3, 7-5 win over unseeded Gael Monfils of France.

Second seed Nadal earlier had pounded Serbian third seed Novak Djokovic 6-4, 6-2, 7-6 (7/3).

Federer will be going for his 13th career Grand Slam title, one short of the record of 14 held by Pete Sampras.

Nadal will have a shot at equalling Bjorn Borg as the only man to win four straight French Open titles. The Swede achieved that feat in 1981.

"The key was the first game when he allowed me to break and after that he was behind all the time," Federer said of Monfils.

"But he held on and battled hard and I am just relieved to have gone through. "It was hard to play against him. He is such a great talent and now he has shown it on a big stage."

Monfils had surprised everyone by getting to the last four as the former world junior champion has struggled to make the step up to the senior ranks and only a few weeks ago was playing on the secondary challenger circuit in a bid to revive his flagging fortunes.

But the combination of a benign draw and a return to the tutelage of former coach Thierry Champion, saw the 21-year-old become the first Frenchman since Sebastien Grosjean in 2001 to make it through to the last four.

But he was immediately in trouble against Federer, who had lost just two sets in his five matches so far, dropping his serve in the opening game and having trouble with his contact lenses as gusts of wind whipped up the red clay dust.

Federer broke again in the seventh game to take the set comfortably in 31 minutes and at the same time quieting the Centre Court home fans on a cool and cloudy afternoon.

Monfils opened the second set with three aces, but two games later he played a poor service game and allowed Federer to break for the third time in the match. Federer, however, inexplicably gifted the break back in the following game and that appeared to galvanise the Frenchman.

The world number one's usually deadly forehand was misfiring badly and he was now the one struggling to save serve.

He did so until the 12th game but with a tie-break beckoning, Monfils lifted his game and levelled the set scores to the biggest cheer of the week on Centre Court. Federer edged his nose back in front with a service break in the third game of the third set which he went on to take 6-3 giving himself the opening serve in the fourth set.

The Swiss maestro had to stave off two break points in the third game of the set after some sloppy volleying at the net and a further two, two games later as Monfils scrambled valiantly to stay in the tie.

The Frenchman incredibly had two more break points on Federer's next serve and again he failed to take advantage.

Federer then had two match points at 5-4 but failed to convert either of them. Two games later though he earned his third match point and this time made no mistake.

Monfils said he felt he had been on the cusp of causing a major Grand Slam upset. "I am disappointed, there was an opening for me there," he said.

"In the fourth set I should have done better with all the break points I had. It was in those moments that I just lacked that bit extra to turn the match around."

AFP