It's maybe my greatest victory - now and until the end of my career I can really play with my mind at peace, and no longer hear that I've never won Roland Garros
French Open champion Roger Federer said he was always confident of eventually winning at Roland Garros - provided Rafael Nadal failed to reach the final.
Federer, who lost the last three finals to Nadal, completed the career Grand Slam on his 11th appearance in Paris with victory over Robin Soderling.
"I knew that the day Rafa wasn't in the final I would be there and I would win," said world number two Federer.
"That's exactly what happened. I didn't hope for it but I believed in it."
Federer added: "It's maybe my greatest victory, or certainly the one that removes the most pressure off my shoulders.
"I think that now and until the end of my career, I can really play with my mind at peace, and no longer hear that I've never won Roland Garros."
Federer's triumph sees him equal Pete Sampras's record of 14 Grand Slam titles and he joins Fred Perry, Don Budge, Roy Emerson, Rod Laver and Andre Agassi as the only men to have won all four Grand Slam events.
The 27-year-old has contested every French Open since 1999 but it was the one major title missing from his CV.
"I had the feeling I gave myself too many opportunities over the years at the French Open," said the former world number one.
"I think Pete was in the semis once. Other players were maybe in the final once. I was in the final three times, and the semis once previously.
"I was able to win Hamburg four times and reach the final of Monaco and Rome."
Federer delighted to win French Open (UK users only)
Federer has now won five Wimbledon titles, five US Opens, three Australian Opens and one French Open but, despite how long he was made to wait for glory at Roland Garros, the Swiss was not prepared to hail it as his greatest achievement.
"I don't want to say it means the most to me, but it's an incredible feeling reaching 14 and not being derailed by losing Grand Slam finals to Rafa (at Roland Garros and Wimbledon in 2008 and the 2009 Australian Open)," he said.
"That I took my time and was able to regroup and equal Pete's record here in Paris is unbelievable.
"Getting the trophy from Andre, who was the last man to win all four majors, seems very fitting."
Sampras won his first Grand Slam title in 1990 and his last in 2002 while Federer, whose first came at Wimbledon in 2003, has equalled the America's tally in half the time.
At 27 he could potentially have several more years at the top level and, in an ominous warning to his rivals, he insisted retirement had not even entered his thoughts.
Having been disrupted by illness and injury in 2008, Federer is now well on the way to silencing the doubters who claimed his career was on the slide.
"It hasn't appeared in my mind once yet that I want to retire," said Federer, whose wife Mirka is pregnant with the couple's first child.
It was very hard mentally for me to stay in the match - I was very nervous at the beginning of the third set because I realised how close I was and the last game was almost unplayable
"Tennis is not for ever, I know that, but I'll try to enjoy it as long as I can.
"I think I still have many more tournaments to go and many more Grand Slams. I'll give it my best shot to have the best possible career.
"I hope I can maintain the records I have going at the moment and break some other ones along the way.
"I hope to stay healthy because motivation and drive is not a problem for me.
"With the changes in my life - getting married and having a baby - it's going to be a very exciting few years."
Federer admitted he went through an "emotional rollercoaster" as he closed in on victory against Soderling.
After being outclassed in a one-sided first set, the Swede put up more of a fight in the second and third sets but never came close to reproducing the kind of form he displayed in beating reigning champion Nadal in round four.
Federer took the second set on a tie-break but, after breaking in game one, was forced to save break points in game four and 10 - when he was serving for the match.
"My good start relaxed me," said Federer. "It was key to stay with him in the second set and not give him any opportunities with my serve. Then I played one of the greatest tie-breaks in my career.
"It was very hard mentally for me to stay in the match. I was very nervous at the beginning of the third set because I realised how close I was and the last game was almost unplayable.
"I was just hoping to serve some good serves and hoping he was going to make four errors. It was that bad. It was an emotional rollercoaster for me."
Soderling has now lost all 10 of his meetings with Federer and admitted he could do little to stop the rot.
The 24-year-old stunned Nadal in round four but claimed Federer was a much tougher opponent.
"Roger's game does not suit my game at all, he does not allow me to be aggressive and he always had me on the run today," said Soderling.
"With Rafa, it's easier to be aggressive. In all my matches against Rafa I think I dictated the game, I dictated the play.
"But against Roger so far it's been impossible to do that."