Frenchman David Gaudu secured his maiden grand tour win when he claimed the 11th stage of the Vuelta, a 170-km mountain trek between Villaviciosa and the Alto de La Farrapona on Saturday.
The 24-year-old beat breakaway companion Marc Soler of Spain with a late burst in the final ascent, a 16.5-km effort at an average gradient of 6.2%.
Gaudu, who impressed in the 2019 Tour as Thibaut Pinot's lieutenant, has been promoted as Groupama-FDJ's sole leader after his team mate pulled out of the race early on.
While he is not a title contender yet, the Breton showed great composure to snatch the biggest win of his career.
"It's such a relief. I had been struggling for days, my legs were hurting and even this morning I didn't feel that great," said Gaudu.
"After Thibaut left the race we stuck together and today we're rewarded. Soler attacked with 500 metres to go and I saw that with the headwind he could not drop me so I waited until 150 metres to go and I gave everything."
The race favourites stayed quiet in the final ascent, reserving energy for Sunday's 12th stage, which ends at the top of the feared Angliru - a 12.4-km ascent at 9.9% with the last seven km averaging a gradient of 13% and featuring a section above 20%.
Slovenian Primoz Roglic retained the overall leader's red jersey, tied on time with Ecuador's Richard Carapaz. Ireland's Dan Martin was in third place, 25 seconds behind.
Enric Mas is still Movistar's best-placed rider in fifth, 1:54 off the pace, 50 seconds ahead of team mate Soler.
Gaudu climbed to 12th, 5:02 behind Roglic.
(Reporting by Julien Pretot; Editing by Toby Davis and Ken Ferris)
