World number three Roger Federer admitted that beating Novak Djokovic in the French Open semi-final almost felt like he'd won the tournament.

Federer will play Rafael Nadal in a fourth French Open final after ending Djokovic's winning run in 2011 with an extraordinary 7-6 (7/5) 6-3 3-6 7-6 (7/5) victory.

The world number two was looking to equal John McEnroe's record of 42 straight wins to start a season and become world number one, but it was not to be and on Sunday Federer will attempt to beat Nadal for the first time at Roland Garros.

It will be the 29-year-old's first grand slam final since he beat Andy Murray at the Australian Open last year, and he was delighted to come through a match that has already been labelled among the best of all time.

Federer, who was also the last player to beat Djokovic at the ATP World Tour Finals in London in November, said: "I wasn't here to spoil the party.

"I was just trying to put in a good match and get to the French Open final, which I'm obviously happy I was able to do. It almost feels like I've won the tournament, which is not the case.

"There was a lot on the line for Novak, a lot of pressure going in, and I thought he handled it great. He got maybe a bit unlucky in the first set, but he hung in there and almost pushed it to five.

"It was a pleasure playing against him. I told him that at the net. I said I think his record speaks for itself, how great he's played already this season, and it's not over yet.

"He can still achieve so much more. I thought we played some great tennis."

Despite the tense nature of the match, in a superb fourth set in particular, Federer, who had gone into the clash without having dropped a set, insisted his belief never wavered.

He said: "I was very confident, especially once I was up 7-6 4-1. I kind of felt like this match is not going to slip out my hands, even though I probably missed another 10 or 15 break points at the end of the second set.

"I just felt you don't give me such a lead and then think you can crawl back into the match. I knew I was probably going to close this out."

After two exchanges of service breaks in the first set, it was Federer who took advantage of a Djokovic error to win the tie-break, and he dominated the second set, breaking in the fourth game and missing a host of other chances.

But a lapse from the Swiss, who won only four games in his last French Open final against Nadal in 2008, at the start of the third let his opponent in and from there Djokovic cranked up the heat.

After clinching the set he broke in the ninth game of the fourth set as both players traded blow for blow at an exceptional level.

With Djokovic serving to level the match, Federer struck back with a brilliant return game and he then saved more break points to take the set into a tie-break.

Again it was the Serb who cracked, a mistake at 3-3 giving his opponent the mini-break, and it was an opportunity he was not about to spurn, clinching victory with an 18th ace as darkness fell.

Djokovic, who has pulled out of the AEGON Championships at Queen's Club, was left to reflect on a superb run, which he admitted could scarcely have ended at a worse time.

He said: "It was the best five months of my life and my tennis career. I cannot complain. It was definitely an incredible period. It had to end somewhere.

"I knew it was coming, unfortunately it came at a bad moment. It was a big match today. But it's sport, I will keep on working hard."

The Serb, who will still be number one if Federer beats Nadal, had not played since Sunday because of the withdrawal of quarter-final opponent Fabio Fognini but he did not believe that was a disadvantage and instead praised Federer for his performance.

Djokovic added: "I think I had a good first set. I was really unfortunate to lose that set. After the first set I slowed down a little bit and he used that to take control of the match.

"But I managed to come back from two sets down against Roger. It's definitely not easy. It's a big match and I tried to think about the first point of the third set as a new match.

"I think I played well. He played really well at the important moments. I congratulate him for a great performance. We were, I think, part of a very good match. It feels bad losing."