The Quick-Step Alpha Vinyl rider completed the race in 4hrs 45min 17sec to storm past Dutchman Robert Gesink of Jumbo-Visma and Mas of Movistar in the final 400 metres of the 191.7 kilometre race.

Gesink, who had maintained his pace following an earlier breakaway, initially held a lead of more than 20 seconds over Mas before the home favourite attacked.

Evenepoel quickly followed and his speed proved to be too dominant for his opponents to contend with as she sailed to victory by two seconds.

The overall leader now has a 2:07 advantage over Mas in the general classification and is 5:14 in front of another Spaniard, Juan Ayuso of UAE Team Emirates.

Evenepoel believes that the race to the title is still not yet over with three stages left.

"I think it’s a new achievement in my life," he said.

"It was a pretty tough stage with really hard climbs in the finale, early attacks from UAE with Almeida…

"The race was really hard, but we always stayed calm.

"I think that’s what I learned, to always stay calm."

He continued: "This was the most perfect day ever.

"Winning La Vuelta is still not done with a really hard stage to come.

"They will for sure attack me.

"But maybe now it’s easier to control because I feel my legs are really good.

"This is very good for me and for the team for the last three days."

Australian Jay Vine of Alpecin-Fenix was forced to abandon the remainder of the tour after he was involved in an early crash and taken away in an ambulance.

His partner, Bre Vine, posted on social media that he was "OK" and that he has not suffered any head injuries.

Stage 19 is scheduled to take place across 132.7km from and to Talavera de la Reina.