While the drops at the top of the 21-kilometer climb reached 24%, Colombian Lopez was able to move away from the other contenders for a stage victory which places him third overall.
Roglic followed the line 15 seconds later, Pogacar losing his wheel in the final meters, conceding another 15 seconds which saw his second place deficit drop to 57 seconds.
Lopez is now third, a minute and 26 seconds later, after Rigoberto Uran passed out late.
“I am very moved,” said Lopez d’Astana. “We dreamed of it, we did it. I think about my family. ”
Grenoble’s 170km stage, with two non-class climbs with summits of around 2,000 meters, would have suited a fit Egan Bernal, but the day started with news that the defending champion had retired from the race after dispatching 18 minutes in two days. as a result of a back injury.
Instead, the Ineos Grenadiers were active again in the breakaway with Richard Carapaz, the last survivor of a hiatus that starred Julian Alaphilippe, Gorka Izaguirre, Dan Martin and Tuesday winner Lennard Kamna when they hit the Col de la Madeleine halfway through the stage.
Carapaz went alone on the final climb, briefly stretching his advantage as the contenders weighed in, but was caught 2 miles from the end as the attacks began in sight of the steeper sections.
Lopez struck for glory shortly after passing Carapaz, but all eyes were on the battle between the two Slovenes battling for yellow.
Roglic easily got back behind the wheel of his Jumbo-Visma teammate Sepp Kuss, then pulled away from Pogacar at the very end as the UAE Team Emirates driver had to fend off overzealous fans who outwardly ignored calls to heed. the race. amid the coronavirus pandemic.
Adam Yates lost time in the final but remains in fifth place, now three minutes and 14 seconds behind the yellow jersey behind Richie Porte in fourth.
“Difficult day, but I stayed there as long as I could so we could be happy with it,” said rider Mitchelton-Scott.
“We have a big stage tomorrow, a lot of uneven, then all we have afterwards is the time trial, one day alone so we will continue. I hope that tomorrow I have good legs. and we will keep trying. ”
Earlier in the day, Sam Bennett stayed glued to Peter Sagan’s wheel and was able to use the intermediate sprint to add two points to his advantage in the green jersey, which now stands at 47 points.
Pogacar led the field over the Madeleine and added the mountain king’s polka dot jersey to his best young rider’s white jersey, but his chances of going yellow before Paris lengthened at the end of the day .