Hushovd retained the race leader's yellow jersey as Garmin-Cervelo revelled in its second victory in succession, having won the 23km team time trial at Les Essarts.
But it was the powerful fast man's decision to act as Farrar's lead-out man - on American Independence Day - that captured the attention of the peloton.
Evans remains third overall - only one second behind Hushovd - after finishing in 35th place in a bunch finish despite a late crash that saw three of his BMC teammates crash.
Hushovd's team-mate David Millar is still in second with the same time as the leader, while defending champion Alberto Contador is still 1min 42secs down.
Evans, who wore the King of the Mountain's polka dot jersey, said there were several dangerous situations.
"We had a few moments today where it was difficult to stay safely in position," he said, having narrowly missed fallen riders, including team-mates.
"Wearing the polka dot jersey today did not help strangely enough as other (teams) do not recognise you and allow you to follow your team-mates.
"Looking at the stage results, I'm guessing even the specialists like HTC-Highroad had similar problems keeping safe and in position.
"Congratulations to Garmin all the same, how nice to see the yellow jersey (Hushovd) leading the sprint - beautiful."
Farrar dedicated the win to Wouter Weylandt, the Belgian rider killed in an accident on the Giro d'Italia, making a W gesture on crossing the finish line.
"I want to dedicate this victory to Wouter," Farrar said.
"It's been a horrible past few months. Everything that happened in the Giro, I've had a lot of ups and downs.
"In the end I wanted to come back and do something to pay tribute. This is the biggest race in the world, and I didn't know it would be possible, but I've trained really hard for this.
"At the moment I can't quite believe I've won it.
"It's fantastic, I've been working to get this for a long time.
"It's the first mass sprint of the Tour, and it's always a bit chaotic. But the team almost made it easy for me.
"We showed yesterday how strong our team is, winning the team time trial. It was a relief, and took the pressure off the shoulders.
"It just keeps on getting better now."
The American also paid tribute to Hushovd.
"The priority was for him to stay in yellow because the last thing we wanted was for a time gap," Farrar said.
"It just shows what a champion Thor is and how classy he is.
"A world champion in the yellow jersey doesn't have to lead out the sprint for a teammate, but I just can't say thank you enough to him."
Kiwi Julian Dean said Hushovd went into the stage prepared to sacrifice his winning chances for the team - and Farrar.
"We had a plan for Tyler, and Thor was part of that plan," Dean said.
"The fact that he’s world champion and leading the Tour doesn’t stand in the way.
"That’s the mark of a true champion."
Hushovd said he was happy to repay his teammates after the team time trial victory.
"The team pulled all day and did a great job to keep me out of trouble," he said.
"It’s extraordinary to win the stage today. We won the team time trial yesterday and I have the yellow jersey, so to win today again is just incredible."
Frenchman Romain Feillu, of Vacansoleil, and Movistar Rojas launched late charges, but Farrar came over the finish half a bike length clear.
The story for the majority of the stage was FDJ rider Mickael Delage, who had a day to remember, winning both the intermediate sprint and king of the mountains points as part of a five-man breakaway before being caught with just 9km remaining.
The Frenchman won the single king of the mountains point on offer when he was first to the top of the bridge into Saint Nazaire, adding to his win earlier in the day in the sprint at Saint-Hilaire-de-Chaleons.