Jonas Vingegaard's attack paid off in style as the Dane took the lead in the Tour de France, severely denting Tadej Pogacar's hopes.
Wednesday's 152kilometre route through the Alps looked set to be crucial in the general classification standings, though few would have predicted this outcome up the Col du Granon.
Pogacar seemed in complete control of the GC and was expected to maintain his advantage, such is his proficiency up the slopes.
Yet led by Primoz Roglic and Wout van Aert, Jumbo-Visma attacked early and lured Pogacar and his fellow UAE Team Emirates riders into responding.
Those early moves seemed to have backfired, with Pogacar and team-mate Rafal Majka looking strong heading onto the final climb, but it all fell apart for the two-time reigning champion when Vingegaard sensed a weakness and lodged a brilliantly timed attack 5km out from the finish, leaving the yellow jersey in his wake.
Geraint Thomas soon followed suit, making his own dent in the GC standings, as for the first time in his career Pogacar showed real vulnerability.
While Pogacar floundered, Vingegaard wrapped up a sensational ride by overtaking Romain Bardet, who is up to second in the GC, and Nairo Quintana to seal his maiden Grand Tour stage triumph.
Thomas pushed over in fourth, with David Gaudu and Adam Yates getting up to the summit before Pogacar – his yellow jersey unzipped and flapping – limped across the line, close to three minutes behind Vingegaard.
"It's really incredible, it's hard for me to put words on," said Vingegaard, whose lead over Pogacar in the GC standings is well over two minutes. "This is what I dreamt of, always, a stage in the Tour. Now the yellow jersey, incredible.
"We made the plan from the start of the day, you can see what it was, we wanted to make it a super hard race in my favour, the favour of Primoz. I took a lot of time today, but I'd never have done that without my team-mates, they were all incredibly strong today.
"On the last climb I was thinking if I don't try, I'm not going to win. Second place is a nice result, but I had this last year, now I want to try to go for the victory."
Van der Poel calls it quits
One of the big names at this year's tour, Mathieu van der Poel, has failed to really get going and he called it a day on stage 11, abandoning the race. It has been a frustrating stint for the Dutchman, who impressed on his Tour de France debut last year. He was dropped on the Lacets de Montvernier, after initially getting involved in the early breakaway.
STAGE RESULTS
1. Jonas Vingegaard (Jumbo-Visma) 4:18:02
2. Nairo Quintana (Team Arkea–Samsic) +0:59
3. Romain Bardet (Team DSM) +1:10
4. Geraint Thomas (INEOS Grenadiers) +1:38
5. David Gaudu (Groupama–FDJ) +2:04
CLASSIFICATION STANDINGS
General Classification
1. Jonas Vingegaard (Jumbo-Visma) 41:29:59
2. Romain Bardet (Team DSM) +2:16
3. Tadej Pogacar (UAE-Team Emirates) +2:22
Points Classification
1. Wout van Aert (Jumbo-Visma) 304
2. Fabio Jakobsen (Quick-Step Alpha Vinyl) 155
3. Tadej Pogacar (UAE-Team Emirates) 148
King of the Mountains
1. Simon Geschke (Cofidis) 43
2. Pierre Latour (TotalEnergies) 35
3. Jonas Vingegaard (Jumbo-Visma) 30