An assured win from Roglič on the Col de Porte has put his rivals on notice for the Tour de France. The star-studded field could do little but watch as the Slovenian powered away in the final 600 metres finishing eight seconds clear of a fast-finishing Thibaut Pinot (Groupama-FDJ) with Emanuel Buchmann (BORA-hansgrohe) third.
Team INEOS had attempted their normal mountain train on the road to the summit finish, starting with an impressive turn from Jonathan Castroviejo that severely reduced the field. Subsequent INEOS riders Michal Kwiatkowski and Geraint Thomas managed to drop Chris Froome along with most of the remaining peloton.
Pavel Sivakov was the final rider from the British squad left to set up Egan Bernal, but swung off with two kilometres remaining, leaving young American Sepp Kuss (Jumbo-Visma) to take over. Kuss blunted an attack from Bernal and then surges from Nairo Quintana (Arkea-Samsic) and Guillame Martin (Cofidis) before Roglič set a sustained pace that Bernal couldn't match with 650 metres remaining.
As riders took off in pursuit, it was in the vain hope of the victory as last year's Vuelta a Espana winner took out the win with a convincing margin.
"It's a great result for our team," Roglič said after the finish. "Once again we show that we prepared right. The whole team did a really great job and I'm happy to finish on top again.
"We all knew about the hard climb at the finish and we started to control the race from the beginning. The guys are really strong so they managed it perfectly and in the end, I was happy to be able to win this."
Roglič has been in red-hot form since the season's recommencement, winning the Slovenian national championships, the Tour de l'Ain overall and as well as two stages of the mountainous race. His performances have thrust into near Tour de France favouritism after now having finished ahead of last year's winner Egan Bernal on three separate occasions on mountain stages in the space of a week.
"Egan [Bernal] is the Tour de France winner so he’s the strongest, or one of the strongest," said Roglič. "But everyone is very prepared and you have to be the best in the end. It was quite a strange season. I’m happy with every race I can do this year and I’m really happy with the way it’s going."
Jérôme Cousin (Total Direct Energie), Geoffrey Soupe (Total Direct Energie), Bruno Armirail (Groupama-FDJ), Kasper Asgreen (Deceuninck-QuickStep), Jasha Sütterlin (Team Sunweb), Fabien Doubey (Circus-Wanty Gobert), Michael Schär (CCC Team) and Australian Ben O’Connor (NTT Pro Cycling) formed the early break of the day for the mountainous 135-kilometre stage from Vienne to Col de Porte.
Jumbo-Visma did the work on the front of the peloton, keeping the breakaway's advantage at no higher than three minutes during the race. Armirail has the last man standing from the move and was left to ride solo to the final climb of the Col de Porte (17.5 kilometres at 6.2 per cent).
Back in the peloton Dan Martin (Israel Start-Up Nation) and Sergio Higuita (EF Pro Cycling) crashed, requiring medical attention before getting back on their bikes.
An energetic start to the climb saw the INEOS train catch Armirail with 8.5 kilometres remaining, with race leader Wout van Aert bidding adieu to the yellow jersey as he left the peloton on the early slopes.
Significant general classification contenders also suffered on the climb, with Rigoberto Uran (EF Education First), Adam Yates (Mitchelton-Scott), Steven Kruijswijk, Tom Dumoulin (both Jumbo-Visma), Tadej Pogačar (UAE Team Emirates) and Romain Bardet all conceding a minute or more on the stage to the eventual winner.
Australian Richie Porte (Trek-Segafredo) was solid for ninth on the stage, ten seconds behind Roglič, a continuation of the form he has displayed so far this season restart.