Roger Federer still does not think Sunday is best but there were no opening-day dramas for the Swiss star at the French Open.

Play began on a Sunday for the first time in Paris in 2006, and Federer voiced his unhappiness at being made to play on that occasion after struggling past Diego Hartfield.

He was up against a qualifier again today in Pablo Carreno-Busta, and it was a match Federer took very seriously given the 21-year-old Spaniard has won 56 matches already this year.

But all his seven titles have come at the third tier Futures level and the step up to facing Federer on Court Philippe Chatrier proved, not surprisingly, too great as the second seed triumphed 6-2 6-2 6-3.

Federer said of the Sunday starts: "I remember they sort of forced me to play on Sunday years back to promote their Sunday thing.

"I was against it just because I felt like the way they got the Sunday, first it was, 'Oh, let's try it out.' Next thing you know they have it for a lifetime or what?

"So I didn't agree with how things went along. From that standpoint today, it is what it is, but it is the only grand slam that has it. Wimbledon does it in 13 days and the French does it in 15.

"So it doesn't make sense, but I do understand that a weekend for tennis is very important for the people who can show up. It is very odd that we start the tournament week on a Monday when everybody goes back to work. It doesn't really work.

"So I get the Sunday start, but it's always something that's a debate within the ATP and the French Open.

"But I'm happy this time around. I told them if they wanted me to play Sunday, whatever, I'm fine with it. They took that opportunity right away."

While it was a straightforward first round for Federer, that was certainly not the case for 15th seed Gilles Simon, who survived a five-set battle with Lleyton Hewitt.

That it went to five sets was not a surprise but there was no shortage of twists and turns as the Frenchman fought back from two sets down for the first time in his career.

Hewitt, 32, rolled back the years as he raced through the first two sets for the loss of only four games, but Simon changed the momentum in the third set and was poised for victory when he moved 5-0 ahead in the decider.

Remarkably, Hewitt won the next five games, saving two match points at 5-2, but he could not complete the comeback as Simon clinched a 3-6 1-6 6-4 6-1 7-5 victory.

The Australian, now ranked 86th, said: "The first two sets I played pretty well. I went out there with a pretty good game plan, I think, and I executed it perfectly for the first couple of sets.

"He changed his game a little bit and gave me absolutely no free points for the next three sets. It wasn't until he was nearly across the finish line that I started getting a couple of cheap points out of him again and he served a lot better.

"I would have liked to have been on the other end of it. It's disappointing but I didn't obviously come here with massive expectations. He's a quality player as well."

Simon insisted he felt calm despite seeing the games slip away, saying: "I do not feel like I did something wrong on those games where he progressively came back.

"It was really difficult. I had to work a lot. It always feels a bit strange.

"I didn't have that much success in the 5-2 game (Hewitt benefited from two net cords). But I felt good. I wasn't feeling I wasn't playing well. Paradoxically, this time I was very relaxed."

Fourth seed David Ferrer was a straight-sets winner, the Spaniard defeating Australia's Marinko Matosevic 6-4 6-3 6-4, while there were also wins for Milos Raonic, Kevin Anderson, Jeremy Chardy, Andreas Seppi and Sam Querrey.