ANDORRA LA VELLA, Andorra -- Sepp Kuss couldn't suppress a wide grin as he raced toward the finish line to become the first American in 10 years to win a stage at the Tour de France.
After winning Sunday's grueling 15th stage, Kuss threw his sunglasses into the crowd and put his arms in the air before covering his face, succumbing to emotion and exhaustion.
Tyler Farrar had been the last American to win a stage at cycling's biggest race in 2011.
"It's incredible, I'm lost for words," Kuss said.
The 26-year-old Colorado native left it late to make his move in the punishing 191-kilometer (118-mile) ride from Ceret at the foothills of the Pyrenees to the tiny mountain-bound nation of Andorra.
"This was Sepp's day," said Jumbo-Visma teammate Wout van Aert, who helped put Kuss in a position to break. "He lives in Andorra and he was looking forward to this stage."
The American attacked going up the 1,796-meter Col de Beixalis and maintained his hard-fought advantage over Spanish veteran Alejandro Valverde, who finished 23 seconds behind.
"To be honest, I was suffering a lot in this Tour de France. I didn't feel like I had the spice in the legs. Today I knew it was finishing where I live, so I was motivated for the stage," Kuss said.
Col de Beixalis was the steepest climb in a day of many ascents in the Pyrenees. Kuss' average speed going up was 20.4 kph (12.7 mph), and 57.9 kph (36 mph) going down, where he clocked a maximum speed of 80.6 kph (50 mph).
"I don't ride to Col de Beixalis much in training because it's so hard, but I knew if I had a good gap, I'd stay away till the finish. Wout van Aert did a great job for me in the valley. It means a lot to me to win a Tour de France stage," Kuss said.
Dutch rider Wout Poels finished third and took over the polka dot jersey for the best climber.
"It's obviously going to be a great battle for the mountains jersey," Poels said.
Race leader Tadej Pogacar enjoyed an uneventful day and remained on course for his second overall victory.
The defending champion was only questioned toward the end of the stage as Jonas Vingegaard followed Ben O'Connor's example with two attacks.
Pogacar answered both without any problems and increased his overall lead to more than five minutes over Rigoberto Uran and Vingegaard.
"I felt good, and I wasn't worried at all about the last climb. I just needed to follow the other riders there, as I did," Pogacar said. "My team did a great job at protecting me all day long, providing me with everything I needed. The key today was to keep myself hydrated, to have water available all the time, and my teammates did that job perfectly."
Guillaume Martin, who was second overall ahead of the stage, dropped back to ninth.
Before the final tussles on Col de Beixalis, riders had to overcome the 2,408-meter Port d'Envalira, where Nairo Quintana made a break after a strong headwind forced riders across the road. Quintana was first to the summit before he was hauled back. Quintana tried again on Col de Beixalis before Kuss took over.
Nacer Bouhanni, who had been suffering since a big crash on Stage 13, quit after the intermediate sprint with 124.5 kilometers remaining.
The rest of the riders have a chance to recover on the tour's second rest day Monday before more climbs await on Tuesday.