(CNN)Tadej Pogacar is poised to become the first Slovenian to win the Tour de France after upsetting his compatriot and hot favorite Primoz Roglic in the decisive time trial on the penultimate stage of cycling's most famous race.
Slovenia's Tadej Pogacar stuns compatriot Primoz Roglic to lead Tour de France
Few gave the 21-year-old Pogacar hope of clawing back the 57-second lead Jumbo-Visma's Roglic held going into Saturday's 22.5 miles test, but he produced one the finest performances in the history of the Tour to win the stage and take the yellow jersey.
His victory on La Planche des Belles Filles was his third of the Tour and gives him not only the coveted yellow but also the King of the Mountains polka dots and the best young riders' white jerseys.
As Roglic faltered on the time trial's decisive climb, the UAE Team Emirates rider crossed the line in 55 minutes and 55 seconds, with a one minute and 21 second advantage over Roglic's teammate Tom Dumoulin and Australia's Richie Porte, who has moved into third place overall after his fine time trial performance.
Roglic, who has been in control of the race with his all-powerful team in support, cracked in the closing miles and now trails Pogacar by nearly a minute with only the final processional stage in Paris to come, where tradition dictates no attempts are made to overhaul the yellow jersey holder.
Pogacar, who is racing the Tour de France for the first time, was stunned by his "unbelievable" performance and paid tribute to his team for its preparations for the decisive stage.
"I'm really proud of the team, they did such a big effort all the way to get the yellow jersey on the final day, it was just a dream," he told Eurosport.
"We did the recon - I knew every corner, every pothole on the road, where to accelerate. It was a road you need to know and that's all thanks to my team.
"My dream was always just to be in the Tour de France, and now I'm here and I've just won before tomorrow the last stage, it's unbelievable."
By contrast, the more experienced Roglic, 30, who won last year's Tour of Spain, felt the pressure of leadership and after a poor change from his time trial bike to conventional road bike for the climb continued to lose chunks of time to Pogacar.
"Chapeau to Tadej, he obviously deserved it," Roglic said. "I just obviously didn't push enough. I was more and more without the power that obviously I needed. I was just giving everything to the end."
The dramatic turnaround had echoes of the 1989 Tour de France when America's Greg Lemond overhauled home favorite Laurent Fignon on the final stage time trial in another massive upset.
Roglic had led the race since taking yellow on the ninth stage, but must now settle for second place, while for 35-year-old Porte it will be his first time on the Tour podium after overhauling Miguel Angel Lopez for the final spot.
Sunday's finish on the Champs-Elysees is traditionally contested by sprinters from each team, with Ireland's Sam Bennett holding a big lead in the battle for the green points jersey over seven-time winner Peter Sagan of Slovakia.