O'Connor climbs to 'brutal' Alpine stage win as Pogacar tightens grip on Tour
Australian O'Connor, 29, took off alone 15km from the finish and navigated the mountain mist to win 1min 45sec ahead of Pogacar atop the Col de la Loze.
Vingegaard crossed the line in third place, nine seconds behind the Slovenian.
"It was brutal, I've never lived anything so hard. The team did well and we had a good plan, but I couldn't take any time off Tadej," said Vingegaard.
Pogacar now holds a 4min 26sec lead over the Dane in the general classification with three days to go before the finish in Paris.