Frenchman Valentin Ferron won stage six of cycling's Criterium du Dauphine on Friday as a long-range breakaway beat the main contenders to the finish line at Gap.
Veteran Pierre Rolland and gritty climber Warren Barguil finished a few seconds back to make it a French podium sweep.
"You don't get many chances like that so you have to take them and that's what I did," said the 24-year-old winner, describing it as the greatest win of his career.
Wout van Aert of Jumbo retained the race lead ahead of two days of racing in the high mountains that will both decide the winner and hint at possible contenders for the upcoming Tour de France.
The 194km run from Rives offered four categorised climbs. When the escape held a four-minute lead on the last one, a 9.1km ascent at 4.6 percent, it became clear they would beat the peloton home.
The main contenders crossed the Gap finish line just 30sec off the pace as Jumbo trio Van Aert, Primoz Roglic and Jonas Vingegaard trimmed the gap over the final 10km.
"We had been hoping to take it easy today, but that was a breath-taking start. We wanted to protect our place in the overall and we did that," said Van Aert.
Ineos Grenadiers' Amstel Gold 2022 winner Michal Kwiatkowski pulled out with a sore knee while UEA's tyro Juan Ayuso suffered a stomach upset and pulled out while in eighth place.
Going into the weekend, Van Aert leads Roglic by 1min 06sec, with Ineos man Ethan Hayter at 1min 32sec.
"Tomorrow a new race starts and we have Primoz in really good shape and ready for that," said van Aert.
Saturday's seventh and penultimate stage takes on the fabled climb of the Galibier mountain at 2,642m altitude. It is the first of three merciless challenges that may decide the 2022 champion.