Primoz Roglic extended his lead in the Criterium du Dauphine when he finished second behind Davide Formolo on the third stage on Friday but Chris Froome continued to struggle.
Italian Formolo (UAE) produced a superb attack from a lead group on the day's big ascent, the Col de la Madeleine, as he opened up a near six-minute gap to the peloton.
He then dug deep on the climb to the finish at Saint-Martin de Belleville, holding on to win by 33 seconds.
Jumbo-Visma's Roglic, tipped as one of the big favourites for the Tour de France which starts at the end of the month, led the chasers home to pick up time bonuses and now leads Frenchman Thibaut Pinot by 14 seconds.
It was a tough day for Team Ineos with four-time Tour de France winner Froome struggling for pace and being dropped from the peloton with 13km of the 157km stage remaining.
Froome finished 15 minutes 51 seconds behind Formolo and looked far from competitive as he tries to nail down a place in the Ineos Tour de France squad.
His team mate Egan Bernal, the reigning Tour champion, finished in the chasing pack but slipped to seventh overall, 31 seconds off the lead.
(Reporting by Martyn Herman; Editing by Christian Radnedge)
