Nairo Quintana snatched the overall victory at the Vuelta al Pais Vasco with an inspired time trial display.
The Movistar man had begun the day four seconds down on overnight leader Sergio Henao, but powered around the undulating 24km loop in Beasain in a time of 35 minutes 23 seconds, which proved 23 seconds quicker than his nearest general classification rival Richie Porte, and pushed both Team Sky riders into second and third places respectively at the end of a hard week of racing.
Quintana may have taken the overall victory, but his ride was only good enough for second place on the stage after world time trial champion Tony Martin (Omega Pharma - Quick-Step) had clocked an unbeatable time, 17 seconds faster than the Colombian.
Benat Intxausti, meanwhile, took third place for Movistar, a further 15 seconds adrift.
The action had taken place in wintry conditions, with rain falling throughout the day and the low temperatures forcing many riders to sacrifice their skinsuits in favour of warmer alternatives.
Only 70 riders started the stage and the result was settled early on with Martin being just the 10th rider to roll down the start ramp and clocking a time no-one else could get close to.
The battle for the GC was a far closer affair, and overall honours were always going to come down to the final five riders, who were separated by just 10 seconds at the start of the day.
Simon Spilak (Katusha) was the first of those to leave, and the Slovenian put the cat amongst the pigeons with a solid ride which yielded fifth place on the day - 19 seconds faster than the next finisher, Alberto Contador (Saxo-Tinkoff).
Porte powered out of the blocks but his time was five seconds down on Quintana at the split, and his Colombian rival continued to build his lead as he passed over the hilly course which ramped up to 12 per cent on one leg-sapping ascent.
Quintana's victory was all but assured when he surged over the line, and while Henao would ultimately lose the yellow jersey, his battling display ensured third place was his by the tightest of margins, and also saw the Team Sky rider top the points classification.
Stage six result
1 Tony Martin (Ger) Omega Pharma-Quick Step, 0:35:05
2 Nairo Quintana Rojas (Col) Movistar, +17secs
3 Benat Intxausti (Spa) Movistar, +32
4 Richie Porte (Aus) Team Sky, +40
5 Simon Spilak (Slo) Katusha, +48
1 Nairo Quintana (Col) Movistar, 21:39:35
2 Richie Porte (Aus) Team Sky, +23secs
3 Sergio Henao (Col) Team Sky, +34
4 Simon Spilak (Slo) Katusha, +35
5 Alberto Contador (Spa) Saxo-Tinkoff, +54