A pileup toward the end of the 218km race south across the Loire River valley under sunny skies cost British champion Bradley Wiggins his hopes of a final podium place in Paris, as Sky's leader crashed out of the race with what the team said later was a broken collarbone.
HTC-Highroad rider Cavendish sprinted out of the speeding pack in the last few hundred metres, beating fellow sprint specialists Alessandro Petacchi and Andre Greipel to the finish.
Cavendish sprinted to victory in the same town where he won his first Tour de France stage in 2008, making the win a special occasion for the British rider.
"It's a very special day for me, it was here where I won my first stage and so it's a very sentimental moment," Cavendish said. "I have to thank the guys for all their work today, it was a hard windy day, and the guys rode hard for me all the way through. They were marvellous."
"The Tour is the biggest race, I love it more than any other, and I really wanted to do the same today as I did three years ago," Cavendish said.
Cavendish gave credit to his teammates for helping him to the memorable win. "It was an amazing leadout, I didn't have to do anything and I'm really proud of them all," Cavendish said.
Cavendish has now taken 27 stage wins in major Tours, including two stages of the Giro d'Italia in 2011, as well as 68 wins on the road since turning pro in 2007. HTC-Highroad has now racked up 42 victories this season alone, making them the most successful ProTour team.
Britain's Team Sky suffered a cruel reversal of fortune, losing their leader and main contender. Wiggins went down along with a few dozen other riders, 38km from the finish. Only 24 hours earlier Wiggins and his Sky teammates were celebrating Norwegian Edvald Boasson Hagen's stage victory, the team's first ever.
Sky manager Dave Brailsford said the crash that took out Wiggins was caused by a sudden slowing by some riders in the peloton.
"I think the guys were moving Bradley up, he went into a tailwind, they knew it was coming. Somebody apparently slammed the brakes on, the whole peloton skidded and then powered into the back of him at a great speed. There's a lot of guys (who) hit the deck," Brailsford said.
Wiggins was competing in his fifth tour and, after winning the pre-tour warm up Criterium du Dauphine in June, had been considered a leading contender for a podium place in Paris.
"He was in the form of his life, I really believe he would have done something here," Cavendish said of his fellow countryman.
Rounding out the disappointing day for Team Sky was Geraint Thomas' loss of the young rider's white jersey, after he finished the stage in a group 306 behind Cavendish.
There was no change at the top of the standings, with Cadel Evans still in second place, just one second behind, and Frank Schleck still in third place, four seconds behind Hushovd.
Race favourite and three-time Tour de France champion Alberto Contador finished the stage safely in the lead group, maintaining the Saxo Bank-SunGard rider's 1:42 deficit in the overall standings.
"We kind of knew that this could be the last very nervous stage so we were extremely cautious and focused on keeping Alberto out of trouble and the boys did a perfect job," said Bradley McGee, the Danish team's sports director. "Now, we're looking forward to go uphill to something that just might be our terrain."
Friday's stage also saw the departure from the race of former world champion Tom Boonen. The 30-year-old Belgian pulled out after he failed to recover from injuries he suffered in a crash on Wednesday.
"Yesterday it was OK, I felt OK, but today I'm really doing bad, my head hurts, I can't concentrate and I'm a danger for my colleagues," Boonen said.
