UAE Team Emirates rider Tadej Pogacar strengthened his lead at the Tour de France after a tough Stage 15 that was won by America's Sepp Kuss. Kuss, 26, became the first American since Tyler Farrar back in 2011 to win a stage on the Tour, coming home 23 seconds ahead of Spain's Alejandro Valverde. He went clear of the leading breakaway group on the ride up the Col de Beixalis with 19km remaining of the 191.3km stage to Andorre-La-Vieille. Pogacar is perhaps the big winner on the day after he was isolated on the windy slopes of the third climb, but kept his calm and, crucially, pace as his closest rivals took turns to attack him. Ineos Grenadiers have said they plan to grind him down in a bid to manoeuvre their own rider, Richard Carapaz, into contention for the yellow jersey. The Ecuadorian currently lies fourth, 5 min 33 sec behind Pogacar. The Slovenian heads into Monday's rest day with an advantage of five minutes and 18 seconds on Colombian Rigoberto Uran with Dane Jonas Vingegaard, Kuss's teammate, in third place a further 14 seconds adrift. Krus made his move with five kilometres of the final category climb to go as the remnants of a powerful breakaway — which had also included Nairo Quintana, Julian Alaphilippe and Dan Martin — split one final time. The 41-year-old Valverde was the only man to sustain a challenge but the Movistar rider could not make an impression on the 14.5km run down into town. Wout Poels led home the next group of riders 75 seconds later, while Martin came in eighth a further seven seconds back. “It's incredible. I'm lost for words,” said Kuss. “To be honest, I've really suffered a lot in this Tour, I just didn't feel I had the … the spice in the legs. “Today I knew it was finishing where I live, and I was really motivated. Finally I had really good legs again so I'm so happy. “My girlfriend and her family were on the final climb cheering me on. I also want to say hi to my parents back home because I haven't seen them in a long time. So I had my family of Spain and my family back home in the US. “I know the final climb fairly well. I actually don't ride it so much in training because it's so hard but I knew the beginning was tough so I knew if I went there and got a gap then I could try to hold it to the finish.” <br/>