Fourth seed Novak Djokovic sent shockwaves around Roland Garros on Saturday when he suffered a 6-4, 6-4, 6-4 defeat by Germany's Philipp Kohlschreiber in the third round on Saturday.
Djokovic was widely seen as the biggest challenger to Rafael Nadal's quest for a fifth successive title as he had come to Paris following runner-up finishes to the Spaniard in claycourt Masters events in Monte Carlo and Rome.
On Saturday, he had looked comfortable leading 4-1 in the opening set before allowing the 29th seed to take control with an array of fierce shots.
"I can't really explain why ... it's just a bad day at the office as they say," the Serb told reporters after his earliest Roland Garros defeat since 2005.
"I didn't find the rhythm, that's all. It was not physically anything. I think it was more mentally just to find that zone, but I couldn't."
Kohlschreiber, along with compatriot Tommy Haas, became the first Germans since Nicolas Kiefer in 2005 to reach the last 16 at Roland Garros.
"I think I played really, really one of the best matches I ever play in a big tournament," Kohlschreiber told a news conference.
"Maybe Novak didn't play his best today. But from my point of view ... I did a really good job today. It was luck and the good game for me today."
Djokovic, a Roland Garros semi-finalist in 2007 and 2008, found himself 5-1 down in the second but saved three set points at 5-2 before breaking to keep himself in it.
Flicking over two beautiful acute-angled forehands to hold in the ninth, the world number four looked to be in the mood for a fight but could not keep up as Kohlschreiber ran him around the court and took the set with a big unreturnable serve.
The pair traded breaks at the start of the third with Kohlschreiber pulling off eye-catching shots like the volleyed lob that had Djokovic scampering back in horror.
Sensing nothing was going his way, the 2008 Australian Open champion looked skywards in mock celebration after holding for 3-2.
"I couldn't believe I made a forehand winner after three sets," he said wryly.
Kohlschreiber, who won a clay title in Munich in 2007, made the breakthrough in the ninth game before serving out the match.
The 25-year-old German, who had never progressed beyond the second round at Roland Garros until this year, will face Spaniard Tommy Robredo, the 16th seed, in the fourth round.