Moments later, he was a giant step closer to clinching a third Tour de France title by winning another tough mountain stage on Friday. Pogacar pulled away from Jonas Vingegaard to be 5 minutes, 3 seconds ahead of his main rival with two days left.
"Now I have a good lead," Pogacar said. "I will do the last two days of the Tour on the roads where I have trained my entire professional career."
The Slovenian looks almost certain to reclaim the Tour crown from Vingegaard, the two-time defending champion from Denmark, and in doing so secure the Giro d'Italia and Tour de France double.
Behind a fading Vingegaard sits Tour debutant Remco Evenepoel of Belgium, who is 7:01 adrift in third place.
Pogacar attacked with about nine kilometers (six miles) left on the final climb of 16 kilometers (10 miles) to the Isola 2000 ski resort. Vingegaard could not follow as Pogacar chased after the Dane's Jumbo Visma teammate, Matteo Jorgenson. The American rider was alone in front with Richard Carapaz and Simon Yates just behind him.
Carapaz and Yates were caught by Pogacar, leaving just Jorgenson ahead. He was overtaken with two kilometers left as the UAE Team Emirates leader soared to his fourth stage win this month — holding up four fingers to the fans — and 15th Tour stage victory of his career.
"As I approached the last two kilometers, I felt a little drained. I still caught Richard Carapaz and Simon Yates and I could catch up with Matteo Jorgenson," Pogacar said. "When it was time to pass him, I pushed as hard as possible to overtake him with speed. He was very strong today, as were all the guys in the breakaway. Hats off to them."
After four hours in the saddle, Pogacar raised both hands in the air as he crossed the line. Jorgensen was 21 seconds behind and Yates 40 seconds back in third. Carapaz was 1:11 back in fourth spot.
"I knew today's last climb very well. With the team, we planned it well and we did exactly as we said," Pogacar said. "Our race was 100% perfect."
Evenepoel placed fifth ahead of a disconsolate Vingegaard, with both riders timed at 1:42 behind Pogacar.
Saturday's 20th and penultimate stage stays in the southern Alps and features three hard category 1 ascents, the last taking the riders up Col de la Couillole.
The Tour ends on Sunday on the French Riviera with a time trail from Monaco to Nice, and not in Paris as it usually does because of the Olympic Games.
Friday's high-altitude stage may have been Vingegaard's last chance to take significant time back from Pogacar.
Two of Vingegaard's Visma teammates — Jorgensen and Dutchman Wilko Kelderman — positioned themselves at the front of a small breakaway and set a strong pace in hot conditions.
The 145-kilometer (90-mile) trek featured two huge climbs known as "hors categorie" (beyond category).
The first came early in the stage, up Col de Vars, and the second just after halfway, to Cime de la Bonette, France's highest road at an altitude of 2,802 meters.
Despite having two riders at the front, Vingegaard did not attack Pogacar.
After a long descent, there was another hard grind to Isola 2000. Vingegaard could not catch Pogacar and, instead, found himself under pressure from Evenepoel, who just beat him in a sprint to the line.
It was a day to forget for Vingegaard, and another one to savor for Pogacar.
"Reaching the score of 15 Tour stage victories is quite formidable," he said.