ALTO DE LAS ALLANADAS, Spain (AFP) - Chris Froome produced a stunning breakaway up a steep summit finish on the 199.8km fourth stage of the Ruta del Sol to take a one-second lead over Alberto Contador into Sunday's final stage.
Contador had held a 27-second lead over the 2013 Tour de France winner after winning their first battle of the season on a mountain finish in Friday's third stage.
However, Froome had his revenge on the gruelling 4.4km climb to the finish line at Alto de las Allanadas to take the stage in 5hr 08min 54sec and grab the narrowest of advantages over his Spanish rival.
Contador was second with Froome's Sky teammate Mikel Nieve back in third.
Froome is now firm favourite to claim the overall win as the final 169.8km stage from Montilla to Alhaurin de la Torre is likely to be decided among the sprinters.