Unseeded Argentine Gaston Gaudio thrashed Lleyton Hewitt 6-3 6-2 6-2 to reach the French Open semi-finals.
Gaudio taught his seeded opponent a lesson in claycourt tennis, using acute angles to send the Australian scurrying all over Chatrier Court.
Hewitt crucially lost serve at 3-4 in the first set, having been 40-0 up, and the 12th seed could find no way back.
Gaudio, in his first major quarter-final, never lost his grip on the match and earned five more service breaks.
"It has always been my dream to win this tournament," said Gaudio.
"But there is a long way to go yet because the two most difficult matches are yet to come."
Hewitt admitted: "He was too good. I didn't feel like I was hitting the ball as cleanly as I'd been hitting over the past week or so.
"A guy like that is confident on this surface and his movement is good. He's a class player on this surface."
Gaudio awaits the winner of Wednesday's second quarter-final between fellow Argentine David Nalbandian and Brazil's Gustavo Kuerten.
Nalbandian could make it three Argentines in the semi-finals, after Guillermo Coria's win over Carlos Moya on Tuesday.