Costa prevailed in a sprint finish, overcoming Germany’s Lennard Kämna of BORA-hansgrohe and Colombia’s Santiago Buitrago of Bahrain Victorious in Lekunberri.

The 36-year-old Intermarché-Circus-Wanty rider rolled back the years to win in 3hr 30min 56sec - 10 years after winning a stage at the Tour de France and capturing the world road race title.

"This team has believed in me from the first moment," said Costa, as reported by Cycling News.

"I started this season in good condition, and now one victory at the Vuelta a España, for me, is very important, and for the team.

"I'm so happy."

Kuss finished 2:52 behind Costa in 19th position as he maintained his lead at the top of the general classification table.

The American holds an advantage of 1:37 over Jumbo-Visma team-mate and closest rival Primož Roglič of Slovenia heading into tomorrow’s rest day before the final six stages.

"I came into the second week with better feelings, and I’m feeling better than in the first week, so I’m getting better," said Kuss.

"It was really fast, really up and down, all day long.

"There were a lot of splits.

"It was important to keep your eyes open because there were moments where Soler was jumping away.

"Primož, Jonas [Vingegaard] and I could play our cards.

"There were some moments when Jonas followed and I didn’t need to go with it, I could also look at other favourites who were trying to protect their top five or top 10 positions.

"It was not an ideal situation with Soler getting in the break, but Jonas getting up there was good and it was good he could bring it back."

There is a rest day for the race tomorrow, with racing due to resume on Tuesday (September 12) with stage 16 running from Liencres Playa to Bejes.