Isaac Del Toro of UAE Team Emirates-XRG maintained his excellent form at the Giro d'Italia to win stage 17 with a perfectly-timed sprint, with the Mexican's first stage victory of the race allowing him to extend his lead in the overall standings.
The 155-km route from San Michele all'Adige to Bormio was less punishing than Tuesday's stage 16, but featured two difficult climbs - Passo del Tonale and Passo del Mortirolo - with a total of 3,800m of elevation.
Del Toro was the freshest man at the end of the final ascent and he broke away from Romain Bardet (Picnic-PostNL) and rival Richard Carapaz (EF Education-EasyPost) with just over 2km left.
Bardet crossed the line four seconds after Del Toro, with Carapaz in third.
Tyrone's Darren Rafferty (EF Education-Easypost) crossed the line over 35 minutes after Del Toro, a minute ahead of compatriot Sam Bennett.
Rafferty drops half a dozen places in the general classification to 86th, while Bennett (Decathlon AG2R La Mondiale Team) is 147th overall.
Del Toro's spectacular effort breathed new life into his bid to win a first Grand Tour and assuaged any doubts that arose after the pink jersey holder saw his lead shrink in a chaotic stage 16 on Tuesday.
"I imagined that I could win a stage with the maglia rosa. The Giro has been very good so far," the 21-year-old said after his win.
"The fight for the podium is incredible. Today I realised that I will never give up. I will always try to win. I have nothing to lose. It wasn't any easier today than yesterday. With the team, we expected some attacks to take place on the Mortirolo.
"We didn't want to let all the GC riders go. I went across to them and I took it easy a bit. I caught them in the descent. We had made this plan with the team that I would attack on the last small climb."
Del Toro, who became only the second Mexican to win a stage at the Giro d'Italia after Julio Alberto Perez Cuapio in 2001 and 2002, now has a 41-second lead in the general classification.
Ecuadorean Carapaz leapfrogged Simon Yates (Visma–Lease a Bike) into second place, with the Briton finishing the stage in fourth place, 15 seconds behind Del Toro.
Earlier on Wednesday, Jay Vine (UAE Team Emirates–XRG) and stage-eight winner Luke Plapp (Jayco AlUla) both abandoned the Giro.
After a string of mountainous stages, Thursday's stage 18 will be a largely flat 144-km ride from Morbegno to Cesano Maderno.
