Colombian climber Nairo Quintana completed an epic day of racing on the Giro d'Italia by claiming victory on the 16th stage and the race leader's jersey from compatriot Rigoberto Uran on Tuesday.
Quintana's hopes of competing for the overall title this year suffered a blow when he tumbled down the standings to 3min 29sec behind Uran after the first two weeks of racing.
But on the first of several gruelling days in the mountains in this final week, the Movistar rider hoisted himself back into contention as Uran and, notably Australian Cadel Evans, ultimately failed to follow Quintana's wheel on a rain-hit descent of the Stelvio climb.
With three tough climbs on the menu Uran was always at risk of being put under pressure by the more proficient climbers in the peloton.
Yet the heavy rain and freezing conditions which prevailed over the first two climbs of the day -- the Galvia (16.5 km) and the Stelvio (21.7 km) -- did little to help the overnight leader's bid either.
Sky rider Dario Cataldo lit the fuse to start hostilities when he attacked from a small chase group on the way to the summit of the Stelvio, whose 2758 metres summit is the highest point of this year's race.
He came over the summit, the road flanked by walls of snow several metres deep, with a 20sec lead on two or three stragglers with Hesjedal and Quintana among another group that had managed to pull away from Uran's main peloton on the way to the summit.
Riding conditions worsened on the descent but Quintana, known more for his skills going up mountains, held his nerve as the chasers kept solo leader Cataldo in their sights and left plenty of nervous chasers in their wake.
Cataldo began the final, 22 km climb to the finish line with a 1:14 lead on Quintana, Rolland and Hesjedal and a three-minute cushion on the pink jersey holder.
But the Italian was soon overhauled as Quintana, Rolland and Hesjedal pressed on together until they steadily dropped back from the Colombian's back wheel.
Hesjedal came over the finish line 7secs in arrears while Uran trailed home 4:11 off the pace and Evans crossed nearly 30secs later.
Quintana, the runner-up at last year's Tour de France, now leads Uran by 1:41 in the overall standings although the day's biggest loser was Evans, who has dropped from second overnight at 1:03 to third overall at 3:21.
Wednesday's 17th stage is a 208 km trek over rolling terrain from Sarnonico to Vittorio Veneto.