Veteran American Chris Horner climbed into the leader's red jersey at the Vuelta a Espana by winning stage three with a late solo attack.
The 41-year-old RadioShack-Leopard rider surged clear of the field just over 1km out from the summit finish on Mirador de Lobeira and held on to win by three seconds.
Alejandro Valverde (Movistar) led home a group of chasers to claim second place, with Joaquim Rodriguez (Katusha) taking third.
Former race leader Vincenzo Nibali (Astana) finished six seconds down in 11th place and drops to second in the general classification, eight seconds behind Horner but six seconds ahead of third-placed Nicolas Roche (Saxo-Tinkoff).
Oldest man in the race
Horner, the oldest man in the race, timed his burst for the line perfectly on the category-three climb, catching and passing lone leader Ivan Santaromita (BMC) 500m out before digging deep for his first Grand Tour stage win.
His triumph came at the end of a dramatic day in which crashes and high winds combined to blow the peloton to pieces.
The 184.8km stage started in Vigo and although a five-man breakaway was allowed to go clear and build up a six-minute gap, they failed to maintain the advantage and saw their lead steadily ebb away.
Behind them, the peloton suffered severe fractures in a pile-up on a tight left-hand bend 43km out, with the likes of Valverde, Nibali and Rodriguez among the big names making up the first group on the road but Belkin's Bauke Mollema marooned in the second.
The incident came at a crucial time, because soon after, the riders left the mainland and crossed a bridge on to the Illa de Arousa, exposing them severe crosswinds on the outbound and subsequent return journey.
Peloton blown apart
It served to widen the splits and Movistar further stretched them by setting a fierce pace, but after lobbying from the likes of Fabian Cancellara and some sterling chase efforts, the peloton eventually came back together with 19km to go.
It was still as one leading on to the lower slopes of the final climb, but then Juan Antonio Flecha (Vacansoleil-DCM) ignited proceedings by launching an early attack.
Italian national champion Santaromita countered, but he too was premature in his move and quickly began to wilt as the race entered the final 1,500m.
Horner made no such mistake, though, pulling clear of the likes of Valverde and Rodriguez to take a surprise victory with a well-executed surge.
Stage three result
1 Chris Horner (USA) RadioShack-Leopard, 4:30:18
2 Alejandro Valverde (Spa) Movistar, +3secs
3 Joaquim Rodriguez (Spa) Katusha, same time
4 Rigoberto Uran (Col) Team Sky, st
5 Daniel Martin (Irl) Garmin-Sharp, st
6 Bauke Mollema (Ned) Belkin, st
7 Michele Scarponi (Ita) Lampre-Merida, st
8 Haimar Zubeldia (Spa) RadioShack-Leopard, +6
9 Nicolas Roche (Irl) Saxo-Tinkoff, st
10 Ivan Basso (Ita) Cannondale, st
11 Vincenzo Nibali (Ita) Astana, +6
1 Chris Horner (USA) RadioShack-Leopard, 9:37:40
2 Vincenzo Nibali (Ita) Astana, +8secs
3 Nicolas Roche (Irl) Saxo-Tinkoff, +14
4 Haimar Zubeldia (Spa) RadioShack-Leopard, +16
5 Robert Kiserlovski (Crc) RadioShack-Leopard, +23
6 Alejandro Valverde (Spa) Movistar, +24
7 Rigoberto Uran (Col) Team Sky, +25
8 Rafal Majka (Pol) Saxo-Tinkoff, +38
9 Roman Kreuziger (Cze) Saxo-Tinkoff, +45
10 Leopold Konig (Cze) NetApp-Endura, +45
18 Joaquim Rodriguez (Spa) Katusha, +56
- Green (points classification): Nicolas Roche (Ire) Saxo-Tinkoff
- Blue polka dot (mountains classification): Nicolas Roche (Ire) Saxo-Tinkoff