Roger Federer believes he is in perfect shape to topple clay-king Rafael Nadal and claim the only grand slam title to have eluded him so far.

The world number one's 10th French Open campaign will begin with a first-round match against American Sam Querrey - ranked 41 in the world.

The Swiss star Federer comes to Roland Garros after finding some good form on the clay in the past few months, having won in Estoril and reached the final in both Monte Carlo and Hamburg.

As ever, Nadal, the reigning three-time champion, will be Federer's main danger but the 26-year-old feels in prime condition to snatch the title off his great rival.

"I think things are looking much better," Federer said.

"It was tough at the beginning of the year but I have definitely bounced back these last few months.

"I'm feeling where I want to be shortly before a really important stretch of tournaments. That starts here in Paris, so I feel good about my chances.

"I'm moving so well, and I haven't any problems after playing a lot of matches.

"I know I can beat him (Nadal). All the chances are here for me to win it."

Second seed Nadal opens up against an as-yet-unknown qualifier while third seed Novak Djokovic, the only player likely to threaten the big two in the men's draw, takes on Germany's Denis Gremelmayr first up.

A vacant women's title is up for grabs in the competition following the retirement of champion and four-time winner Justine Henin.

Maria Sharapova, Serbian duo Ana Ivanovic and Jelena Jankovic as well as 2002 winner Serena Williams should be main challengers.

Henin announced last week she was quitting the sport to make a "new start", a decision which surprised Federer.

"I think it's quite sad," said the men's world number one. "It's a pity for tennis when the very top player quits.

"I hope she has good reasons because it's an extreme decision, I believe.

"She said she almost succeeded in everything in her career but what I'm surprised about is her timing because it was so sudden, before the French Open which she was coming to as the major favourite."