American Chris Horner sneaked into the overall lead of the Tour of Spain with just two stages remaining as Spaniard Joaquim Rodriguez produced a stunning final burst to win the 19th stage on Friday.
Katusha rider Rodriguez attacked with just over a kilometre of the 181km ride from San Vicente de la Barquera to Oviedo remaining to finish 11 seconds ahead of Italy's Diego Ulissi and teammate Dani Moreno.
Forty-one-year-old Horner came in fifth, six seconds ahead of overnight leader Vincenzo Nibali, to move just three seconds ahead of the Giro d'Italia winner in the general classification.
"It's always nice to have the red jersey again. I didn't expect it today, I thought maybe tomorrow," Horner told Spanish television station TVE afterwards.
"It's a big surprise. The climb was hard but not that hard. It was more a game of tactics. I had Nibali on my wheel when Rodriguez attacked so I let him go to force Nibali to chase."
Despite his win, Rodriguez didn't move up any places in the general classification. However, he reduced the gap on those in front of him and is now just 1min 57secs behind Horner and 51secs off compatriot Alejandro Valverde in third.
"If we didn't win today, tomorrow would be very difficult because Chris has shown that he is very strong. Today was our last chance," said a relieved Rodriguez.
The penultimate stage of the race on Saturday is arguably the most daunting yet as the finish line is at the top of the Alto de l'Angliru, a 12.2km climb with an average gradient of over 10 percent.
And with such a demanding climb to come, Rodriguez believes he is now in with a chance of not only securing a place on the podium, but fighting for the overall victory.
"It is a beautiful finish (in Oviedo), for any climber to leave their mark on the top is very special and today has been an incredible confidence boost.
"I hope to be at my best and to also have the chance to win tomorrow."
However, Horner is confident he will still be wearing red when the race descends on Madrid for its largely processional finale on Sunday.
"At the moment the legs are fantastic. I like the very steep climbs so, if the legs are the same tomorrow, I think I should have the jersey in Madrid."
As in previous days the overall race leaders stayed together in the peloton and only really looked to attack one another on the final climb up the Alto de Naranco to the finish.
However, once the peloton had caught an early breakaway attempt by Portuguese rider Jose Joao Mendes up the category two climb, there was no doubt who the winner would be once Rodriguez exploded up the final kilometre to open up a huge gap on his competitors that was never threatened.
And Nibali's bid to add a second Tour of Spain title to the one he won back in 2010 continued to wilt as, just like in Thursday's finish in Pena Cabarga, Horner and Valverde also had stronger legs in the final few metres to move away from the Italian.