Pinot celebrated in style across the line, punching the thin, oxygen-poor air as he conquered the iconic ascent.
The man in yellow Julian Alaphilippe resisted the Tourmalet's 17km onslaught, finishing a close second to his compatriot as more credentialled climbers like defending champion Geraint Thomas and Richie Porte were distanced.
Deceuninck-Quick Step's star rider now boasts an overall race lead of over two minutes to nearest rival Thomas.
Pinot and Alaphilippe embraced after the stage, the folklore of the infamous peak not lost on the Frenchmen.
"It's one of my best ever wins," Pinot said. "Every Tour stage win is special, but when you're a climber, winning stages on L'Alpe d'Huez or the Tourmalet stays with you for life."
"Today I was perhaps the strongest," Pinot said. "I could not leave the Tour without a stage win and this one I had checked. I'm building my palmares little by little, and I love winning stages like this.
"I have always had this rage of victory in me. The more you win, the more you want to win, I want to relive those emotions.
"The next goal is to find the final podium in Paris. I have eight days left, and I will do everything I can to get there.
"My team (Groupama-FJ) is very strong, Jumbo-Visma too, the level was very homogeneous and that is perhaps why the Ineos team could not dominate like the other years."
The shorter, 111km stage got off to a rapid start in Tarbes, a breakaway of 15 riders escaping early. Polka dotted Tim Wellens (Soudal Lotto) went on the attack, claiming maximum points over the top of the Col du Soulour.
Several of the favourites for the climbs showed weakness early. Romain Bardet (AG2R La Mondiale) dropped off the back of the bunch 61 kilometres from the finish and was never sighted at the front of the race again.
Adam Yates was distanced soon after and while his Mitchelton-Scott team mates dragged him back to the peloton, he could not cope on the Tourmalet's early slopes.
The break still led the race in the valley between the two major climbs with the peloton holding their reins. Romain Sicard (Total) attacked in an attempt to be the last man standing from the early group, but Elie Gesbert (Arkea-Samsic) overtook him with determined riding.
But Gesbert too was dragged back as the general classification stars began their battle. Warren Barguil (Arkea-Samsic) attacked first but the resolute pace-setting of David Gaudu (Groupama-FDJ) brought his countryman back into the fold.
A succession of attacks and counterattacks followed as the riders surged through the throngs of spectators at the peak of the famed climb. Riders were dropped at each injection of pace, with Australian hope Richie Porte losing contact five kilometres from the top, finishing just over two minutes behind Pinot.
Thomas was another high-profile casualty, though his time loss was less severe after showing weakness with less than two kilometres remaining, conceding 36 seconds to Pinot. His team mate Egan Bernal fared better on the climb finishing just eight seconds down on the stage.