Italy's Giulio Pellizzari won stage 17 of the Vuelta a Espana, with Britain's Tom Pidcock in second as Jonas Vingegaard extended his overall race lead.
Pellizzari, 21, launched an attack 3.5km from the end of the 143.2km route on the punishing slopes of the summit finish on the Alto de El Morredero.
Pidcock was next to cross the line from a small group of general classification favourites that had gone clear on the climb, with Pellizzari's Red Bull-Bora-hansgrohe team-mate Jai Hindley in third.
Vingegaard was fourth, two seconds ahead of his main rival Joao Almeida, who is now 50 seconds adrift of the Dane in the GC race.
Thursday's 18th stage is a 27.2km individual time trial around Valladolid, with the race finishing on Sunday in Madrid.
Earlier on Wednesday, riders in the peloton had voted to neutralise the stage in the event of a disruption, rather than race to an undefined finish, which has been a feature on days disrupted by pro-Palestine supporters on the Grand Tour this year.
And in an interview with news agency Reuters, the vice president of the rider's union Pascal Chanteur said they could decide to quit the race altogether if there are further incidents due to safety concerns.
"The riders voted by a majority to stop in case of a new problem. They will then decide whether to continue or to end the event," said Chanteur.
Bahrain Victorious rider Jack Haig, added: "Unfortunately we're being caught in the middle of something that maybe doesn't even really involve us.
"At the moment we are kind of just the pawns in a very large chess game that unfortunately is affecting us."
An individual clutching a Palestine flag caused a crash on stage 15. The team time trial on stage five was also disrupted when the Israel-Premier Tech team, owned by Israeli-Canadian businessman Sylvan Adams, were stopped on the road by a group of protesters holding Palestinian flags.
Tuesday's stage 16 ended eight kilometres before the scheduled finish, while several other stages of this year's race including stage 11 - which was shortened without a winner - have suffered the same issues.