Slovenia's Primoz Roglic assured victory in the Vuelta a Espana on Saturday and needs only to complete the short ceremonial run to Madrid on Sunday to lift his first Grand Tour.

The 29-year Jumbo Visma rider, a former ski-jump champion, leapt into the overall lead in the individual time-trial last week, and maintained a healthy advantage under constant pressure over a string of tough mountain stages. 

Saturday's 20th stage was won by another Slovenian Tadej Pogacar, who not only secured the white jersey as best under-25's rider, but climbed to third place in the overall standings with his third stage victory here.

Pogacar of the UAE Emirates Team is the breakout star of the Vuelta, and deprived Colombia's Miguel Angel Lopez, one of the great animators of this tour, of the white jersey.

The youngster attacked from within an elite group of riders with 30km to race and produced a relentless show of power.

He and his compatriot Roglic need only finish Sunday's run into Madrid that is fully expected to finish in a mass bunch sprint, to climb onto the podium in Madrid.

Jumbo-Visma provided Roglic with a solid platform from which to take his victory, surrounding their leader with a strong team after he failed to close out the Giro d'Italia in May.

The victory emulates the performance of Simon Yates in 2018, who had looked set to win the Giro before wilting, and then redeeming his reputation by winning the Vuelta.

World champion Alejandro Valverde of Spain's Movistar team assured second place, but his teammate Nairo Quintana, who started Saturday in third dropped to fourth.

The 39-year-old Valverde was all smiles however at the finish line.

"You'd say I was the one who won the Vuelta," the affable Movistar captain joked about the mob of journalists mobbing him on a chilly, bleak hilltop.

"I'll be honest after Pogacar left I couldn't hear a thing in my earphones up here and I thought I'd lost second place, so in fact I'm pretty happy."