The peloton climbs into the hills 50-kilometres into the stage to Burgos...

David Millar rode stage four modeling socks from the new George Hincapie line of sportswear...

A small crash splits the peloton as the climb of the Puerto del Escudo begins after 55-kilometres...

Four riders break clear on the 1st-category climb - Felix Cardenas leads Leonardo Piepoli, Gustavo Otero and ONCE's Isidro Nozal (right)

Hincapie himself was hard at work up-front, setting the pace to test US Postal's rivals in this Vuelta...

With teamate Nozal safely in the escape, race-leader Joachin Rodriguez was able to take it easy behind Hincapie's group...

Eight riders have formed an escape over the top of the Puerto del Escudo - Jurgen Van Goolen leads Cardenas, Oscar Laguna, Fabien Jeker, Jose Gutierrez, David and Unai Etxebarria....and Nozal

With less than 25-kilometres to go, and over two minutes down on the escape, the US Postal team suddenly upped the pace...perhaps unhappy with Nozal's lead?

Almost immediately, the ONCE team jump ahead of the Postal team...perhaps trying to ruin the chase of Nozal, or waging a psychological war with Roberto Heras's team?

Up-front, Jeker has been knocked to the ground by a Guardia Civil motorbike - he is about to be passed by the warring peloton...

Meanwhile, Unai Etxebarria has taken off alone with eight-kilometres to go...

...and wins alone into Burgos

Isidro Nozal becomes the new-race leader for ONCE.