Former champion Serena Williams shocked the French Open crowd, and herself, by losing to Virginie Razzano in the first round on Tuesday, her earliest exit from a grand slam in the 47 appearances she has made in an outstanding career.
Razzano was two points from defeat in the second-set tiebreak but battled back to knock out the fifth-seeded American 4-6 6-7 6-3 in two minutes over three hours.
Williams had been the pre-tournament favourite and her shock exit overshadowed Tuesday's other events, with men's defending champion Rafa Nadal, fourth seed Andy Murray and former women's winner Francesca Schiavone among those winning easily.
Three days of watching the favourites cruise through the first round in the sunshine, had lulled the Roland Garros fans into a gentle doze.
Williams, last up on the Philippe Chatrier showcourt at the end of another summery day, was supposed to swiftly dispatch local heroine Razzano and complete the second-round line-up.
Razzano, though, had other ideas. She woke up the drowsy fans with her battling play and, by the time she got to her eighth matchpoint in a 25-minute final game, the crowd were in a frenzy.
As Razzano skipped around the court in delight after her win, a dejected Williams gathered her bag and headed straight for the news conference room to try to explain what had happened.
"There is no excuse," the 13-times grand-slam singles champion said. "I just didn't play at all the way I have been practising."
Razzano, whose fiance died from a brain tumour last year, was struggling with cramp as she served in the extraordinary final game which went to deuce 12 times.
The Frenchwoman, ranked 111 in the world, saved five breakpoints and squandered seven matchpoints before Williams hit a groundstroke out on the eighth.
"It's the most beautiful victory in my career," Razzano, 29, said in a courtside interview.
Nadal had bad news for anyone thinking of thwarting his bid for a record seventh French Open title: this year he feels even better than he did when he won his sixth, 50 weeks ago.
After speeding into the second round with a 6-2 6-2 6-1 thrashing of Italian Simone Bolelli, Nadal, who came to Roland Garros with three claycourt victories behind him this season, declared his confidence to be sky-high.
"I feel fresher than last year. My attitude is more positive," the Spanish world number two told his post-match news conference.
"Last year my attitude was good because I wanted to fight for it but I was perhaps not positive enough. I was not cool enough, cool-tempered, whereas this year I'm extremely motivated. I feel a lot better when I'm out on the courts."
Nadal, who won in Rome eight days ago, and in Barcelona and Monte Carlo last month, was certainly in impressive form as he saw off the world number 111 in just under two hours.
He was soon joined in the second round by fourth seed Murray who comfortably beat Roland Garros debutant Tatsuma Ito of Japan 6-1 7-5 6-0 on Suzanne Lenglen Court.
Scot Murray will now play Finn Jarko Nieminen, while Nadal faces Uzbekistan's Denis Istomin.
Italian Schiavone and Russian Maria Sharapova, who has won every grand-slam event except the French, both enjoyed a fine start to this year's tournament.
Schiavone, the winner in 2010 and runner-up to Li Na last year, overcame pre-match nerves to defeat 41-year-old Japanese Kimiko Date-Krumm, the third-oldest woman to play here in the professional era, 6-3 6-1.
Sharapova, who could reclaim the world number one ranking depending on the fortunes of Belarussian Victoria Azarenka here, inflicted the first whitewash of the tournament when she sped past Romanian Alexandra Cadantu in 48 minutes.
Former world number one Caroline Wozniacki of Denmark and Wimbledon champion Petra Kvitova also had straight-sets wins, over Greek Eleni Danilidou and Australian Ashleigh Barty, the tournament's youngest player at barely 16, respectively.
In the men's draw, Serbian eighth seed Janko Tipsarevic recovered from losing his focus when an elderly spectator, overcome by the heat on Court One, was helped from the court in mid-play, to beat American Sam Querry 2-6 6-4 7-6 6-3.