On the summit of Santuario del Acebo, one of the toughest mountain stages of the Vuelta a España, American Sepp Kuss (Jumbo-Visma) escaped to claim the biggest victory of his career.

On a day that clearly defined Jumbo-Visma's domination of this year's Vuelta, Kuss was given the go-ahead to win while teammate and overall leader Primoz Roglic handled the attacks of his GC rivals.

Roglic later said that Kuss had no problem riding alone and congratulated his teammate on his first Grand Tour stage win. He also noted that he was strong enough to defend his overall ranking if necessary.

"I had good legs myself, so I was fine," Roglic said.

Kuss, who celebrates his 25th birthday next week, was overjoyed with his early birthday present. He beat Ruben Guerreiro (Katusha) and Tao Geoghegan Hart (Team Ineos) by more than 30 seconds in the last 500 meters and exchanged high-fives with the fans.

"I knew the first few kilometers of the climb would be the hardest, so I tried to get a good position and ride in my own rhythm. I didn't play mind games," Kuss said.

"I wanted to run at my own pace and I had a little reserve in case Primosch showed up. Maybe a little too early to go, but I felt good."

With four kilometers to go on the final climb up Esebo, Couss was already away and widening the gap. It was a clear improvement from last year's Vuelta, where he started well but lost a lot of ground by the third week.

"At this point last year, I was completely dead. It was getting harder and harder to stay in the lead group, and I was very tired," said Cus, who finished 65th in last year's Vuelta.

"But I learned a lot from this year's Giro, and I'm much better in this year's Dauphiné."

Kuss acknowledged that his team dominated the race, with Tony Martin doing a great job leading the main peloton during the break. This despite losing Steven Kruisweig to injury.

"When there is a selection we have all the numbers. [It is the passion of the fans that makes the Vuelta so special.

"They support us not only on good days, but also when we are suffering from being 30 minutes behind. That's what makes cycling such an incredible sport."