The 25-year-old Cavendish thrust his arms skyward and hugged teammates in the winner's circle after beating Germany's Gerald Ciolek and Edvald Boasson Hagen, of Norway. Cavendish had faded in a sprint finish in Wednesday's stage won by Italy's Alessandro Petacchi, and bared his frustration by hurling his bike after the fourth stage.
"It's incredible, it's been a long time," said Cavendish of his victory. "Yesterday wasn't that great for us. I let the guys down."
Cavendish has developed a reputation among some as a "bad boy" of cycling. He was fined by international cycling's governing body, UCI, this spring for making a hand gesture that was deemed unsuitable after he won a sprint finish in a Tour de Romandie stage.
Breaking down during a TV interview, after holding his face in his hands, HTC Columbia rider Cavendish admitted the "pressure was immense," said he had "been through a helluva lot," and denied that he had thrown his bike down a day earlier.
"I just want to thank all the people who supported me," he said.
With Cavendish pausing to cry, Fabian Cancellara came up and put his arm around him.
"Sprints are never easy," Cancellara said. "They're psychologically very hard. Today, we saw a nice thing: After all the buzz around him -- the young sprinter, the big mouth and all that -- he's a real sprinter."
Thor Hushovd of Norway, who wears the best sprinter's green jersey that Cavendish covets, and who has had tensions with him in the past, said: "Good to see him back today after all the problems he's had."
France's sports minister, Roselyne Bachelot, who was on hand for the stage, was beaming about Cavendish's display of emotion.
"Only sport can give us scenarios like this," she said. "The one who was called 'the bad boy' for several days became not only the good boy but the absolutely superb boy."