Team Sky's Chris Froome has moved second overall in the 69th edition of the Vuelta a Espana after following an attack 3km out from Astana's Fabio Aru, who won Stage 18 of the race on the summit finish at Monte Castrove en Meis.
Tinkoff-Saxo's Alberto Contador retains the race lead, 1 minute 19 seconds ahead of Froome, who leapfrogs Movistar's Alejandro Valverde following the 157km stage from A Estrada.
Froome finished 1 second behind Aru, who was third overall at May's Giro d'Italia, but crucially a dozen seconds ahead of the chasing trio of Contador, Valverde, and Katusha's Joaquin Rodriguez.
The Team Sky man had started the day 3 seconds behind Valverde on the general classification, but now has a 13 second cushion on him in the overall standings.
The race concludes with a short time trial in Santiago de Compostela on Sunday, while tomorrow's stage gives a final chance to the stronger sprinters.
That means that the last chance for a big change in the overall classification will come on Saturday, when the race tackles a summit climb at Puerto de Ancares.
