O'Connor mounted a long-range assault from the early breakaway, digging deep in the worst conditions and hardest climbs of the race so far to take a well-earned stage win in his debut Tour while also rocketing into GC contention.
The West Australian came into the day 14th overall and eight minutes behind Pogacar, but when the dust had settled at the finish in Tignes he'd knocked over six minutes off that gap and moved into second overall, now just 2 minutes and 1 second off the 2020 champion.
While the attention turned to O'Connor and his blistering ride, Pogačar went about launching his own attack, riding to the fore of the chase group with his teammates in support before embarking on another solo assault up the final climb to finish sixth on the stage and remind everyone what he's capable of.
The Slovenian paid O'Connor his dues after the stage as he revealed a little worry crept in as it looked at one point like he may lose the maillot jaune to the West Australian.
"Hats off to O'Connor he was really strong and almost took yellow off me," Pogačar said.
"I was a little bit scared of that. It wouldn't have been the worst thing to lose it but I kind of like the colour.
"I want to keep it for as long as possible. So I made a small attack and I closed a little gap. All in all, I'm in a good place."
With every other GC rival now over five minutes back as the peloton heads into the first rest day, Pogačar admitted O'Connor may be a legitimate contender for his throne if today's stage was anything to go by.
"He's riding really well," Pogačar said.
"Today he made a huge effort so I don't know what that cost him in such demanding weather. I think potentially he's a good GC rider. He is super strong, super young. For sure he is in contention."
When asked about the tactics of INEOS Grenadiers, who attempted to make up time on the mountains but were burned again by the Slovenian, Pogačar welcomed their motivation to make the race interesting in what was a brutal stage on the riders bodies.
"It was a hard day and super-demanding," he said.
"Maybe we weren't turning out very high Watts but you get those hard legs at the end. They tried and I respect that. But I gave my best to counter-attack. I was also worried that if I didn't maybe others would go for it, too."
He also defended his UAE teammates after criticism was again directed their way for not supporting him at the finish.
"I don't understand why everybody keeps saying the UAE team is bad and that we don't have things under control," Pogačar said. "We are one of the strongest teams in the race and I am in the leader's jersey. For now, we are one of the best Tour teams, for sure."
The Tour de France will take a well-earned rest day, before returning with an expected sprint stage, 191 kilometre stage from Albertville to Valence. Watch from Tuesday evening at 2030 AEST on SBS, SBS OnDemand and the SKODA Tour Tracker for all the action from what has been a tumultuous Tour de France.
