PARIS -- Surely a guy who's played the longest match ever doesn't have anything left to worry about when he plays these days.
"I'm going to have a problem," he said. "My wife is a complete fan of Roger. And my family is as well. So I'm going to have to tell them not to make a mistake about the box [they sit in]. That's the first thing."
There were no such challenges for Mahut in his defeat -- upset is too strong a word considering the circumstances -- of Andy Roddick in the first round. That win was supposed to be the icing on the Frenchman's 10th and probably final French Open appearance. When he spoke to reporters after his four-set win, it was clear how much it meant to him.
He thanked officials for putting him on Court Suzanne Lenglen, the tournament's second show court. "It was a gift given to me, and I seized this opportunity. I'm really happy," he said.
"We all hope to play such a match on such a court here with the French. This was the time for me. I wanted to make the most of it. I wanted to stay on the court. And at the age of 30, there we are. It happened."
It's easy to understand Mahut's exuberant reaction. In his past nine appearances at his home Slam, he had won only one match. Returning to the headlines by defeating a big-serving American also had a bit of reverse symmetry with his famous 70-68 in the fifth loss to John Isner at Wimbledon in 2010.
And he was happy to finally get a win against Roddick, who had beaten him four previous times.
"When I see him in the locker rooms, I'll feel better," Mahut said. "I won't feel like [such a] a pigeon."
The most excruciating of those losses against Roddick came in the final of Queen's in 2007, when Mahut had match point to win what would have been his first title. It remains the closest he has come to winning an ATP tournament.
Then, a week after captivating the upscale Queen's spectators with his diving volleys on the manicured club lawns, Mahut was back on the ragged grass courts of Roehampton, trying to qualify for Wimbledon. He made it and reached the second round of the main draw.
This is the story of Mahut's career, one of minor successes but major heroics -- the kind that gives the tennis circuit its color and character. And occasionally, like against Isner at Wimbledon or Roddick at Queen's, he burst into prominence and grabbed the interest of the general public.
This week has been one of those occasions. After the local fanfare over his Roddick win, Mahut followed up by beating 2006 junior French Open champ Martin Klizan to set up the third-round encounter against Federer. Mahut even landed on the front page of the national sporting newspaper, L'Equipe, which ran a big photo of him with his arms spread above his head.
Mahut believes his long-awaited success comes from finally deciding to be his net-rushing self.
"I decided to play aggressive, even in the French Open," he said. "I didn't think I should play differently because it was clay, because it was a slower surface. This year I go up to the net, I'm aggressive, and if it goes in, all the better."
And now, playing Federer, in France, likely on the Court Philippe Chatrier main stadium -- it's no exaggeration to call it the biggest matchup of Mahut's career, not counting the unanticipated history of the Isner match or the hype surrounding their unexpected rematch at Wimbledon a year later.
The only problem, as Mahut sees it, is likely to be the result: "Of course I have very few chances of winning it. I don't have a lot of room for victory, but I'm going to try to use my weapons," he said. "I need to play the best match of my life, and he just needs to play an average match."
It doesn't sound like this match will break any longevity records. But for Mahut, it'll still be one to remember.