Nairo Quintana of Colombia was poised to win the Giro d'Italia at the first attempt after holding off his rivals in the penultimate stage, a 167-km mountain ride won by Australian Michael Rogers on Saturday.
Tinkoff-Saxo rider Rogers, who was last month cleared of wrongdoing after a positive test for clenbuterol last year, was the strongest rider involved in the 20th stage's early breakaway, beating Italians Franco Pellizotti and Francesco Bongiorno for his second stage victory of the tour.
Bongiorno was with Rogers in the finale but was cost time when he lost his balance after being touched by a spectator.
Nicolas Roche (Tinkoff-Saxo) finished the stage in fourth place - 1:35 seconds behind Rogers to move up to 30th in general Classification.. His compatriot Philip Duignan (SKY) was placed 131st and is 42nd overall.
Tour de France runner-up Quintana, 24, was never bothered by his rivals in the final ascent, an intimidating climb up the Monte Zoncolan at an average gradient of 11.9 per cent over 10.1-km.
The Movistar rider arrived almost five minutes behind Rogers, just ahead of compatriot Rigoberto Uran, who remains second overall, 3:07 behind.
Italian Fabio Aru, who crossed the line some 15 seconds behind, is still third.