No amount of talent, touch or topspin could save Switzerland's Roger Federer on Monday as the gifted Roland Garros fifth seed fell to Peru's Luis Horna 7-6, 6-2, 7-6 in the biggest shock on day one of the claycourt Grand Slam.

Touted as a pre-tournament favourite, Federer's French Open nightmare continued as he fell at the first hurdle for the third time in five years.

Horna, making his Roland Garros debut, was well worth his victory, earned in two hours and 11 minutes.

The writing was, perhaps, on the wall for Federer who had looked less than focused as he warmed up for the match several hours before taking to Centre Court.

Hitting in the empty arena before the Stade Roland Garros gates were opened to the public, Federer flicked the ball casually around the court rather than grooving his strokes.

He was made to pay for his relaxed approach by the metronomic determination of Horna, who chased and harried his feted opponent throughout.

"Disappointing today, definitely," the Swiss said afterwards. "He didn't play a bad match and I didn't play a good match, the one definitely helps the other, you know?"

Horna, however, was elated. "This is the best feeling I have had in my whole life," said the Peruvian, who last month became a father for the first time.

"BIT ANXIOUS"

"I was a bit anxious playing here for the first time but my coach said 'go out there and don't waste the opportunity -- it might not come again'.

"So I played just the way my coach told me to play and it was perfect."

In the women's field, Serena Williams huffed and puffed her way past Germany's Barbara Rittner 6-2, 6-1 to get the defence of her title off to a solid enough start.

The one-sided scoreline proved an accurate reflection of the pattern of play, but it was only the top seed's overwhelming power which gave her such simple passage in 53 minutes.

Rittner's guile and finesse had kept her in the contest for the first four games, which the pair shared, but when the muscle-bound champion turned up the power there was no contest.

"It was really fun to be out there...fun to be back where all the magic began for me," the top seed said.

"I definitely felt pretty good. Usually when I go into the first round of a grand slam I'm a little bit nervous -- I mean, no-one wants to lose first round.

"But here I am definitely where I want to be."

Men's 10th seed Paradorn Srichaphan is nowhere near where he wanted to be on day one of the tournament, having been dumped at the exit 6-4, 3-6, 6-0, 7-5 by Slovak Dominik Hrbaty.

The popular Thai has endured a rough claycourt season, chalking up only two wins on the surface in 2003, and he failed to buck the trend at Roland Garros against the determined Hrbaty.

NO MISTAKE

Eleventh seed Rainer Schuettler made no mistake, though, beating America's Cecil Mamiit 6-1, 2-6, 6-4, 6-2 while Moroccan 23rd seed Younes El Aynaoui beat France's Anthony Dupuis 6-4, 6-4, 6-4.

Emilie Loit gave French fans something to cheer about, downing 29th-seeded Russian Elena Likhovtseva 6-3, 6-2 while Japanese 16th seed Ai Sugiyama beat Spanish doubles specialist Virginia Ruano Pascual 4-6, 6-4, 6-4.

Fourth seed Justine Henin-Hardenne strolled into the second round, beating Patricia Wartusch 6-3, 7-5.

Testing her Austrian opponent throughout, the Belgian saved her best tennis for when it counted, unfurling her unparalleled backhand at key moments to secure victory.