Chris Froome maintained his slim hopes of claiming the Vuelta a Espana title despite missing out on victory on stage 18 atop Monte Castrove on Thursday.
The conclusion of the 157-kilometre route from A Estrada featured two ascents of Monte Castrove and one of the final opportunities to accrue time.
Italian Fabio Aru (Astana) beat Froome to the line, but the Team Sky leader stole crucial seconds from Alejandro Valverde (Movistar) to move second behind overall leader Alberto Contador.
Dan Martin was 12th, 48 seconds behind Aru, to retain sixth place in the overall classification.
Philip Deignan was 8 mins 11 secs back to move up one place to 44th overall.
Contador (Tinkoff-Saxo) now leads Froome by one minute 19 seconds after the Spaniard finished fifth, 13 seconds behind Aru.
Valverde fell to third, 13secs adrift of Froome and 1min 32secs behind Contador.
It is unlikely Contador will relinquish the red jersey before Sunday's concluding short individual time-trial in Santiago de Compostela, but stranger things have happened.
Friday's 180.5km 19th stage is from Salvaterra do Mino to Cangas do Morrazo.
Luis Leon Sanchez (Caja Rural Seguros) was the last of the day's breakaway riders to be caught, with 15km remaining, ahead of the final finishing ascent.
Froome's Team Sky squad led the peloton and the 2013 Tour de France winner nicked a few bonus seconds at the intermediate sprint with 8km to go.
The real action took place on the second climb to the finish, with Warren Barguil (Garmin-Shimano) attacking. The Frenchman has been linked with a move to Team Sky in 2015.
Barguil's move was short-lived as a select group caught him and the counter attacks continued, with Katusha attempting to help their leader Joaquin Rodriguez.
Jerome Cappel (Cofidis) then made his move before Fabio Aru (Astana), who began the day in fifth, accelerated.
Rodriguez followed, with Valverde, Contador and Froome chasing him.
Froome then jumped towards Aru with 2.5km to go and Contador, Valverde and Rodriguez did not follow.
Froome caught Aru, with the pair cresting the summit together before making a bid for the finish line.
Aru was able to claim victory, but Froome's move saw him enhance his podium ambitions and keep his dream of a possible second Grand Tour title alive.
