The battle for Tour de France supremacy looks like being an all-Slovenian affair after Tadej Pogacar won stage 15 to close the gap on race leader Primoz Roglic while Egan Bernal saw the defence of his title ended on the unforgiving slopes of the Grand Colombier.

Pogacar took victory and bonus seconds on the line just ahead of fellow Slovenian Roglic, cutting his deficit to 40 seconds as the 174.5km stage from Lyon delivered another shake-up to the general classification going into Monday's rest day.

Bernal began the day third, 59 seconds down, but cracked early on the 17km climb to the summit finish and surrendered more than seven minutes to tumble out of the top 10.

That the Colombian was dropped at a time when Roglic's Jumbo-Visma team-mate Wout Van Aert – a man who has won two sprints in this Tour so far – was setting the pace on the front suggested his problems ran deeper than mere fatigue.

"Today I have lost three years of my life," said Bernal, who began the Tour complaining of an injury suffered in the Criterium du Dauphine last month but indicated his problems came down to a lack of power in the legs.

"The back problem is not an excuse. The team must now rethink what we are looking for until the end of this Tour."

The 23-year-old's collapse means the Ineos Grenadiers, formerly Team Sky, are out of contention going into the final week of a race they have won in seven of the past eight years.

Their problems were apparent even before the final climb with Bernal quickly losing team-mates. This has been a strange season for so many reasons, not least the lack of racing, but the new-look squad at this Tour, minus Chris Froome and Geraint Thomas, has not sported the resilience of old.

Now it appears to be a battle of two Slovenians, and two close friends who may find those bonds tested over the next week.

"It was a really difficult stage and in the end I was waiting for the sprint so I'm happy to win again," said UAE Team Emirates' Pogacar, who doubled up on his stage nine success.

"I don't know what happened (to Bernal) but Jumbo did a really high pace and some riders paid for it."

With the race heading into a rest day on Monday before the final battle for yellow, the 21-year-old Pogacar added: "For the moment (Roglic) looks unstoppable but today Bernal cracked, one day maybe I can crack, or Roglic.

"You never know in a three-week stage race so there are still opportunities."

Van Aert ate into half the mountain before pulling over, dropping back to follow Bernal over the line some seven minutes and 20 seconds down.

Roglic could not quite finish off the job and deliver a stage win, but declared himself satisfied with the day's work despite the looming presence of Pogacar.

"Obviously Tadej is really strong, but I have to say our guys today were incredible," Roglic said. "I really wanted the win at the end but Tadej was a little too strong, but it was a good day for us.

"For sure it would be better to gain seconds but he was better today. Anyway, I am happy with how it went."

Adam Yates tried an ambitious attack seven kilometres from the summit but it did not last long before the Mitchelton-Scott rider dropped back in, and at the end of the day he found himself moving up in the general classification as others dropped away.

Rigoberto Uran now moves up to third, a minute and 34 seconds down from Roglic, while Yates sits fifth, two minutes and three seconds from the yellow jersey he held for four days last week.

"I wanted to try something just before the rest day," Yates said. "I've been getting better day by day. I didn't want it to come down to the last kilometre or two because on previous days I've waited and suffered to hold the wheel.

"I went and tried to get over the steep bit to the flatter section for a rest, but Jumbo weren't happy with me trying something so reeled me back.

"But overall the sensations were good. It's a rest day and then hopefully some good stages in the Alps."

Sam Bennett, having picked up two further points on Peter Sagan to strengthen his grip on the points leader's green jersey, made it home with five minutes to spare before the time cut.