PARIS (AP)—Five major champions successfully made their way through the first round of the French Open on Sunday's opening day. One didn't.

Sam Stosur and Svetlana Kuznetsova were first up on the main two courts, and both won in straight sets. Juan Carlos Ferrero and Juan Martin del Potro soon followed on the same courts, and with similar results. And 2008 French Open champion Ana Ivanovic then made it 5 for 5.

The lone loser so far was Andy Roddick, the 2003 U.S. Open champion from the United States.

''It's a bit of an early start, but always nice to get through it now,'' said Stosur, the U.S. Open champion who beat Elena Baltacha of Britain 6-4, 6-0. ''You have the whole day and whatever else to recover and, yeah, enjoy.''

Roddick lost to 88th-ranked Nicolas Mahut 6-3, 6-3, 4-6, 6-2, exiting in the opening round of a Grand Slam tournament for the first time since 2007. The 26th-seeded Roddick is 7-10 this season, 0-4 on clay.

Seven-time Grand Slam champion Venus Williams was also playing Sunday. Williams is playing in a major tournament for the first time since revealing she was diagnosed with an autoimmune disease that causes fatigue.

None of the top three men was in action on Day 1. Top-ranked Novak Djokovic and Roger Federer will be on court Monday, while Rafael Nadal is slated to begin his attempt for a record-breaking seventh French Open title on Tuesday.

The ninth-seeded Del Potro made his way into the second round despite some problems with his left knee, beating Albert Montanes 6-2, 6-7 (5), 6-2, 6-1.

The 2009 U.S. Open champion played with tape on his knee early in the match. Del Potro then added wrapping after a massage from a trainer following the second set.

''It's a problem when you can't find your balance like you're used to, but I'll use these few days of rest to get better,'' Del Potro said. ''If I go on the court, it's because I feel good. I want to continue playing.''

Del Potro reached the semifinals at Roland Garros in 2009, but lost to eventual champion Federer in five sets. A few months later, the Argentine defeated Federer in the U.S. Open final.

Ferrero, the 2003 French Open champion, beat Jonathan Dasnieres de Veigy of France 6-1, 6-4, 6-3. The 32-year-old Spaniard is one of 37 men in this year's draw that is 30 or older, an Open era record for Grand Slam tournaments.

''I saw myself in the mirror, and when I walk on the court I don't think about whether I'm younger or older. The only thing I try to do is play well,'' Ferrero said. ''And I'm at Roland Garros, and the idea is to play well today.''

Jo-Wilfried Tsonga, the highest-seeded player in action on Sunday at No. 5, also advanced. The Frenchman defeated Andrey Kuznetsov of Russia 1-6, 6-3, 6-2, 6-4.

Fabio Fognini of Italy was the first man to reach the second round Sunday, beating Adrian Mannarino of France 6-0, 7-5, 6-1. No. 21 Marin Cilic of Croatia was next, defeating Daniel Munoz-De la Nava of Spain 6-4, 6-4, 7-5.

Kuznetsova won the French Open title in 2009 and the U.S. Open in 2004 but is seeded No. 26 this year. Against Mirjana Lucic of Croatia, the Russian faced little trouble despite being broken twice in the second set. She eventually won 6-1, 6-3.

''I love this tournament. Even before I won I always enjoyed coming here,'' Kuznetsova said. ''It's (a) special atmosphere here.''

Ivanovic beat Lara Arruabarrena-Vecino of Spain 6-1, 6-1. The 13th-seeded Serb won her only major title at Roland Garros in 2008, but then lost in the fourth round a year later. She fell in the second round in 2010, and then lost in the first round last year.

No. 10 Angelique Kerber of Germany and No. 20 Lucie Safarova of the Czech Republic also advanced to the second round, along with American players Melanie Oudin and Irina Falconi.

The French Open is the only Grand Slam tournament that starts on a Sunday. The other three all start on Mondays.

''I don't think it's too big a deal now that it's more of a proper schedule,'' Stosur said. ''I think the first year there was only a handful of matches, and, yeah, if you were on the schedule then, it really didn't feel like the tournament started. Nobody else was thinking that the tournament had started.''