Katusha rider Dani Moreno claimed the host nation's first stage win of the 2013 Vuelta a Espana on Tuesday, while Italy's Vincenzo Nibali regained the overall lead.
Nicolas Roche finished the fourth stage in tenth place to remain third overall. He is now eight seconds adrift of the leader and maintains his lead in the mountain classification.
Dan Martin has risen five places in the general classification and lies in 28th place.
Moreno, who finished second on Sunday, made his attack with less than a kilometre to go on the finishing climb of the 189km stage from Lalin to Fisterra and overhauled Juan Antonio Flecha to take the victory and earn the second Vuelta stage win of his career.
Fabian Cancellara and the rest of the chasing pack tried to haul Moreno back in but the 31-year-old had timed his move to perfection to finish in a time of four hours, 37 minutes and 47 seconds.
Swiss ace Cancellara (RadioShack Leopard) had to settle for second place, with Michael Matthews (Orica-GreenEdge) third, Gianni Meersman (Omega Pharma-Quick Step) fourth and Bauke Mollema (Belkin Pro Cycling Team) completing the top five.
All of the top 21 riders were awarded the same time, including Italian Nibali (Astana) who regained the red jersey after finishing in the first chasing group while previous leader Chris Horner of RadioShack Leopard was in the second group, six seconds back.
Nibali, the 2010 Vuelta winner and 2013 Giro d'Italia champion, now boasts a three-second lead over Horner with Roche, riding for Team Saxo-Tinkoff a further five seconds back.