Carlos Moya became the highest seed to fall at this year's US Open in a shock five-set defeat to Olivier Rochus.
Rochus stunned the third seed with a 4-6 6-4 6-3 6-7 (5-7) 7-5 win.
Moya looked out of danger when he broke for 4-3 in the decider, but Rochus went on to play some inspired tennis in one of the matches of the tournament.
And in a disappointing end, Moya delivered his eighth double fault on match point to hand Rochus a fourth-round place against Dominik Hrbaty.
Hrbaty upset 15th seed Paradorn Srichaphan 7-6 (10-8) 6-3 6-3.
Moya was still in shock as he tried to explain his defeat to the unseeded Rochus.
"I had so many chances but if I didn't win it's because I didn't deserve it," he said.
"It is very disappointing. I was playing better every day and practising very well.
"I thought I was going to win. Even when I lost the second set I was playing well. But when I lost the third I knew it would be tough to beat him."
Rochus, at 5ft 5ins the shortest man in the draw, had not won a match in his previous four visits to the US Open and said his victory over Moya was the biggest of his career.
"That was the best match ever," he said.
"The atmosphere was phenomenal for me. Everything, my game, the crowd. I think I
will never forget this match, that's for sure."