Nairo Quintana holds the red jersey after he took command of the Vuelta a Espana by gaining key time on his general classification rivals with a stage 10 victory on Monday.
Movistar's Quintana, winner of the Giro d'Italia in 2014, surged to victory atop the Lagos de Covadonga to underline his title credentials.
The Colombian eased past Robert Gesink (Lotto NL - Jumbo) with under three kilometres of the 188.7km ride from Lugones left to seal his first individual stage win in the Vuelta.
Quintana finished 24 seconds clear of Gesink and 25 seconds ahead of Team Sky's Chris Froome in third, meaning he now leads the general classification by 57 seconds from team-mate Alejandro Valverde. Tour de France champion Froome is a second further back.
Gesink went on a solo break with 6.5km to go, leaving Pierre Rolland (Cannondale) and Egor Silin (Katusha) in his wake.
Quintana and Alberto Contador (Tinkoff) were 50 seconds down the road at that point, but attacked as they each attempted to take control of the GC.
Froome had been 45 seconds behind that duo, but a remarkable recovery saw him cut that gap to 20 seconds, forcing Quintana and Contador to push again.
And it was Quintana that proved the stronger as he dropped Contador with an assault that Gesink was no match for.
Briton Froome, accompanied by Valverde, soon caught Contador before opening up a gap on the three-time champion, who finished down in eighth - a 65 seconds behind Quintana - to leave him fifth in the GC.
Valverde - who holds the green points jersey - took fifth behind Omar Fraile (Dimension Data) with Sunday's winner David de la Cruz (Etixx - Quick Step) surrendering the red jersey as he finished over three minutes off the pace.