Leader Joaquin Rodriguez held off his nearest rival Alberto Contador to win the 12th stage of the Vuelta a Espana.
The Spanish pair broke away from the peloton on the 190.5km stage from Vilagarcia de Arousa to the summit finish of Mirador de Ezaro.
Fellow Spaniard Alejandro Valverde was third, while Britain's Chris Froome finished fifth to maintain his third place in the general classification.
However, he lost ground on the leaders and now trails Rodriguez by 51 seconds.
It was the second stage win of this year's 21-stage Vuelta, which finishes in Madrid on 9 September, for Rodriguez.
Stage 13, on Friday, is a flat stage from Santiago de Compostela to Ferrol.
Stage 12 results:
1. Joaquin Rodriguez (Spain/Katusha) 4:24:32"
2. Alberto Contador (Spain/Saxo Bank) at +8"
3. Alejandro Valverde (Spain/Movistar) +13"
4. Robert Gesink (Netherlands/Rabobank) +20"
5. Chris Froome (Britain/Team Sky) +23"
General classification after 12 stages:
1. Joaquin Rodriguez (Spain/Katusha) 44:50:35"
2. Alberto Contador (Spain/Saxo Bank) at +13"
3. Chris Froome (Britain/Team Sky) +51"
4. Alejandro Valverde (Spain/Movistar) +1'20"
5. Robert Gesink (Netherlands/Rabobank) +2:59"