Reigning Vuelta a Espana champion Primoz Roglic (Jumbo-Visma) took the leader's red jersey on this year's race with an emphatic solo win on stage 17 on Wednesday.
Roglic, who broke away from the pack alongside Egan Bernal (Ineos) with 60 kilometres remaining, dropped the Colombian with 7.5km left to go solo up the climb and claim a third stage victory, 1:35 ahead of the chasers.
Bernal eventually finished the stage seventh after being caught by a chasing group, with Roglic's American team mate Sepp Kuss taking second spot.
The Slovenian race leader has a 2:22 advantage over second-placed Enric Mas (Movistar). Odd Christian Eiking (Intermarche-Wanty-Gobert Materiaux), who had been in red at the start of the day, crashed on a descent, finishing 9:20 back.
“It was a really impressive day. When Primoz went with Bernal, the pace before that was already really hard,” Kuss said.
“It was a brave move to go that far out, but I could tell he really wanted to do something today and he did it an impressive way.
“Tomorrow there’s another crazy hard climb and anything can happen – everyone will be tired after today.”
Wednesday’s vicious 186-km stage contained four major climbs, starting with the third-category Altu de Hortigueru inside the first 40km.
It was on this first climb that an eight-man break was reeled in by the peloton as the rain began to pour down.
A large group of GC contenders remained together until the second ascent of the first-category Collada Llamena 60km from the end of the stage, when Bernal attacked and Roglic promptly followed.
The duo worked together until the early slopes of the hors-categorie Lagos de Codavonga climb before Roglic pulled away as the inclines reached 16 per cent.
The race remains in the Asturian mountains on Thursday with another summit finish on the 162.6-km course from Salas to the Alto d’el Gamoniteiru.