Team Sky’s Froome had strengthened his group on the overall lead yesterday, when he triumphed in the individual time trial.

The 180.5km route from Villadiego to Los Machucos proved a different test today, with the Briton suffering on the tricky summit finish.

He was unable to respond when Colombia’s Miguel Angel Lopez and Spain’s Alberto Contador attacked in the closing six kilometres of the stage, as they sought to chase down Denifl, the final member of the early breakaway group.

Italy’s Vincenzo Nibali and Russia’s Ilnur Zakarin were also able to put the pressure on Froome, as the pair sought to boost their general classification hopes.

Despite being chased down by Contador, Denifl was able to hold off the Trek-Segafredo rider to earn victory in a time of 4hr, 48min and 52sec.

The Austrian delivered a historic result for Aqua Blue Sport, with the victory being the Irish Professional Continental team’s first at a Grand Tour race.

Contador was forced to settle for second place at 28sec down, while Lopez, Nibali, Zakarin and Poland’s Rafal Majka were 1:04 behind the winner.

The focus turned to the time gap to race leader Froome, who eventually came in 42sec behind his main rivals.

Froome still holds a 1:16 advantage over Bahrain-Merida’s Nibali, with the Team Sky rider aiming to become the third rider to win the Tour de France and Vuelta in the same year.

The Netherlands’ Wilco Kelderman is 2:13 down on the race leader with four stages remaining, while Zakarin is 2:25 off the pace.

Tomorrow will see the riders tackle a 169km route from Suances to Santo Toribio de Liébana.