Barring a crash in Sunday’s final stage from Fuenlabrada to the centre of Madrid, 29-year-old Roglic will earn his first grand tour victory and become the fist Slovenian to win one of cycling’s three biggest races.
Roglic came fifth in the gruelling 190km mountain stage —containing five climbs — from Arenas de San Pedro to Plataforma de Gredos nine seconds behind world champion Alejandro Valverde, who is set to be the overall runner-up.
Roglic holds a lead of two minutes and 33 seconds over Valverde, while Pogacar is practically guaranteed third place and a spot on the podium after another superb solo display.
“I’m just relieved. It was the last really hard day in the mountains. A Slovenian won again, it’s nice. The closer we get to the end, the harder it gets. I stayed in my position and I’m really happy.
"I crashed quite hard yesterday. But we’ve showed in the past days we are really strong and we showed it again today. Everyone did an amazing job.
"Until now, I was only smiling only in secret. It’s a nice feeling not to have big mountains anymore, but there’s still one day. And then hopefully tomorrow we can smile even more."
Pogacar, 20, formed part of the general classification group for the bulk of the stage but attacked on the penultimate climb to target the breakaway group containing Tao Geoghegan Hart and Ruben Guerreiro.
“It definitely took patience," he said. "My legs felt good but the morale wasn’t that high in the first part of the stage. Then I saw everybody was uncomfortable with the cold and the rain. I felt good in the last climb and I attacked.
"Lopez had done a big effort and I chose the right moment. I had good support on the road from Slovenian fans, from my family and from the team car. They gave me incredible motivation, and I went full gas for last hour.
"It will be an honour to stand on the same podium as Valverde and Roglic. It’s really incredible. I never imagined this. It will take me some days to understand what I’ve done.”
The youngster, who has had an astonishing debut grand tour, did not stay with the duo for long and launched a solo attack which saw him steadily increase his advantage as he crested the Puerto de Pena Negra climb alone.
Pogacar never looked like relinquishing his lead and came over the finish line at the summit of Plataforma de Gredos one minute and 32 seconds ahead of second-placed Valverde to collect his third stage win of the Vuelta.
The 2019 La Vuelta a España concludes with a processional sprint stage in Madrid. Watch it live on SBS Viceland and streaming via our website and SBS On Demand from 1am AEST.