DE-LUCHON, France- Alberto Contador underlined his Tour de France potential in beating Nairo Quintana to win the third stage of the Route du Sud on Saturday.
Although there is still another stage to go in the four-day race across the south of France, Saturday's 181km mountainous run from Izaourt to Bagneres-de-Luchon in the Pyrenees was always viewed as the decisive stage.
The 32-year-old Tinkoff-Saxo leader attacked Colombian Quintana on the final climb of the day but although he could not drop him, Contador made the difference on the descent into the finish.
He came home 13 seconds ahead of the Movistar leader and will almost certainly now win the race.
Both riders sprung a surprise by entering the Route du Sud instead of traditional pre-Tour warm-up races the Criterium du Dauphine or Tour of Switzerland.
For both it is their final race before the Grand Boucle begins on July 4 in Utrecht, the Netherlands.
They will be among the favourites for overall victory alongside champion Vincenzo Nibali and the man he deposed, Chris Froome.
Young French climber Pierre-Roger Latour, 21, took third on the stage in Bagneres-de-Luchon.