Tadej Pogacar stands to claim a stunning overall victory in the Tour de France after his friend and fellow Slovenian Primoz Roglic cracked in a dramatic time trial on La Planche des Belles Filles.
Roglic began the day with a 57-second advantage in the yellow jersey he has worn for 11 days, but it all went wrong for the pre-Tour favourite in the 36.2km time trial which ripped up expectations before Sunday's traditional procession into Paris.
In one of the most dramatic finales to a Tour since Greg Lemond snatched yellow off the shoulders of Laurent Fignon in Paris in 1989, Pogacar won the stage in a time of 55 minutes and 55 seconds to claim the yellow jersey as well as the King of the Mountain's polka dots and the best young rider's white.
Roglic shipped almost two minutes on the day, his team-mates Wout Van Aert and Tom Dumoulin watching on in stunned silence as they saw their own hopes of stage victory go up in smoke alongside Roglic's grander ambitions.
It completed a remarkable three weeks for Pogacar, making his Tour debut and riding only his second Grand Tour after third place in the Vuelta a Espana – won by Roglic – last year.
This was his second stage win of the race, and only underlined his strength after he conceded 81 seconds in crosswinds on stage seven.
"I think I'm dreaming," Pogacar said before his interview was interrupted by Roglic, who came in to embrace the new race leader.
"I really don't know what to say, it's unbelievable. I don't know when I will get this. 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.
"We were dreaming that from the start and we achieved that and it's just amazing. It was not just me, it was all the team. 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."
Roglic was behind Pogacar in the splits almost from the start, with his ride unravelling completely on the final climb after a slow bike change.
"I just obviously didn't push enough," he said. "I was more and more without the power that obviously I needed. I was just giving everything to the end.
"I can still be happy with the result and the racing we showed so let's take the positive things out."
Richie Porte rode the time trial of his life, finishing third to overhaul Miguel Angel Lopez and claim his first career podium finish in the Tour in what the 35-year-old admits will be his last entry as a team leader before his expected move to the Ineos Grenadiers next season.
One of his future team-mates, Adam Yates, slipped back on the penultimate day but hung on to a top-10 finish, ninth overall.
Sam Bennett's sole mission was survival, staying inside the time cut to keep him on course to win the points classification in Paris on Sunday.
The Irishman has a lead of 55 points over Peter Sagan – winner of the green jersey a record seven times – and could have the classification wrapped up by the intermediate sprint on the run in to Paris, which would leave him free to concentrate on a potential stage win on the Champs-Elysees.
"I think when I arrive into the Champs-Elysees and that first lap it's going to be another thing that's going to be amazing, I'll probably have a tear in my eye," Bennett said.
"It's something you always dream about. I'm looking forward to the occasion and doing the best race we can possibly do and seeing if we can take home another stage."