Italian Valerio Conti eased to a commanding victory in stage 13 of the Tour of Spain, the longest of the race, finishing 55 seconds clear of his closest challengers and over half an hour ahead of the peloton.

Colombian Nairo Quintana retained the red jersey, maintaining his 54-second lead over Tour de France champion Chris Froome and his 65-second advantage over Alejandro Valverde after the trio finished together in the peloton.

The 23-year-old Conte raced clear of the five-man chasing pack with 19km left in the 213km stage from Bilbao to Urdax-Dantxarinea and never looked back, becoming the youngest rider to win a stage on this edition of the Vuelta.

Danilo Wyss, Sergey Lagutin, Michael Gogl, Vegard Laengen and Yves Lampaert finished together behind the Italian, Wyss taking second and Lagutin third.

"We knew that the breakaway would go to the end because we had a huge advantage. We knew it would be difficult because the previous days have been taxing, but for me, it was the perfect day," Conti told reporters.

"I felt really good, it was the right stage for me, it was the right breakaway, and when I attacked it was because I felt I was able to give everything.

"It's my first victory in a Grand Tour and it's a great feeling. This morning I felt perfect."

Saturday's stage is a 196km ride from Urdax-Dantxarinea to Aubisque-Gourette with a high-mountain summit finish.