The Deceuninck-QuickStep rider pipped Lotto Soudal’s Caleb Ewan to the line with former team-mate Peter Sagan taking third for Bora-Hansgrohe.
Bennett’s success saw him claim the green jersey while there were no major changes in the general classification with Primoz Roglic retaining the overall lead.
The Slovenian will carry a 21-second advantage over defending champion Egan Bernal into stage 11 with Guillaume Martin of Cofidis seven seconds further back.
Britain’s Adam Yates, of Mitchelton-Scott, was 62 seconds behind Roglic.
Bennett’s win fulfilled a long-held ambition and completed a set of grand tours stage wins after previous triumphs at the Giro d’Italia and Vuelta a Espana.
The 29-year-old was emotional as he spoke to media after his win and admitted he did not initially think he had done enough.
“I don’t think it has hit me,” he said. “I forgot to throw the bike at the line and I thought he had got me. I thought I’d be in floods of tears but I’m just in shock.”
Bennett’s voice began to crack as he thanked his team, friends and family.
“Sorry, I don’t mean to be a cry baby,” he said.
“You dream of it and never think it’ll happen, then it does. It took a while for it to hit me.”
The sprint ended an eventful stage which began on another island, the Ile de Oleron, and featured long stretches on an exposed coastal route.
It was not overly blustery and the terrain was flat but crosswinds made for some anxious moments among the peloton, as did numerous road hazards such as roundabouts, traffic islands and narrow roads.
There were a number of crashes, one of which accounted for Mitchelton-Scott’s Sam Bewley, who was forced to withdraw.
