American veteran Christopher Horner moved back into the leader's red jersey after winning the 10th stage of the Tour of Spain on Monday.
It was the RadioShack rider's second stage win of this year's Vuelta following his third stage success that also saw the 41-year-old wear red for a day, before losing it to Italy's Vincenzo Nibali.
The Astana rider finished second on the punishing mountainous 187km stage from Torredelcampo to Alto de Haza Llana, which included 18 percent ramps in the final stages, losing 48 seconds to the American with Spaniard Alejandro Valverde third at just over a minute back.
Horner broke clear on his own in the final kilometres and quickly edged out a significant gap as the other overall contenders marked each other's responses.
Eventually Nibali kicked for home and got clear of the other chasers, but by now Horner was already well on his way to victory.
Horner leads Nibali in the overall standings by 52 seconds with Valverde third at 1min 08sec.
Overnight leader Daniel Moreno lost over two minutes to drop outside the top five.
Tuesday is the first of two rest days before Wednesday's individual 39km time trial around Tarazona. – AFP