Gaston Gaudio fought back from two sets down to win a bizarre French Open final 0-6 3-6 6-4 6-1 8-6 as Guillermo Coria suffered with cramp.
Coria dominated early on but played the fourth set at walking pace and served with difficulty in the closing stages.
The crowd were stunned into silence, but Coria was soon fit enough to twice serve for the match in the fifth set.
But cramp, or possibly nerves, saw him waste two match points and Gaudio came through in three hours 31 minutes.
Gaudio received the trophy from Guillermo Vilas, who was the last Argentine to triumph at Roland Garros in 1977, before the country's national anthem was played.
The newly-crowned champion paid tribute to Vilas.
"I want to thank Guillermo Vilas because it's thanks to him that we both started to play," said Gaudio.
"Since I was a kid it was a dream for me and now I'm here it's too much for me.
"Guillermo was playing unbelievable during these two weeks and for sure he'll get this title next year."
Coria had looked on course for an embarrassingly easy victory after an hour as Gaudio appeared paralysed by nerves.
But it was Coria who suffered with victory in sight and Gaudio hit back to take a tight third set.
With the score at 1-1 in the fourth, Coria called for the trainer and had both legs massaged.
And to the amazement of both spectators and his opponent, the world number three strolled through the next five games, protecting his injury.
After five breaks of serve in the fifth set and with Coria moving without difficulty, if still serving at half-pace, he served for the match at 5-4.
That game disappeared to love and another opportunity went begging at 6-5 as Coria wasted two match points with loose groundstrokes.
Gaudio needed no further invitation and raced through the next two games to claim a hugely unexpected first Grand Slam title.
The Roland Garros crowd responded with sympathy to Coria's plight, giving him a lengthy ovation after he picked up the runners-up plate.
"I want to congratulate Gaston, he's had some problems and come through them," said Coria.
"I'll be back next year."