France's Nans Peters crossed the line alone to claim his maiden victory in the Giro d'Italia 17th stage on Wednesday as Ecuador's Richard Carapaz tightened his grip on the leader's pink jersey with four days of racing left.
Peters, riding for the Ag2r-La Mondiale team, blew away his rivals at the end of the 181km run through the north of Italy, near the Austrian border.
The 25-year-old pulled clear 16km from the line and had built up an advantage of one minute at the foot of the 5.5km final climb.
"It's enormous! I'd never won, I'd always come close," said the rider from the mountainous region of Isere in south-eastern France.
Colombian Esteban Chaves, riding for Mitchelton-Scott, finished a distant second 1min 30sec behind with Italy's Davide Formolo of Bora-Hansgrohe third at 1min 51sec.
"It's incredible to get my first pro win in a Grand Tour," continued Peters.
"My Giro was already a success having worn the top young rider's white jersey for a few days. I had no stress."
Peters had already been among the leaders in the sixth stage, but had been unable to finish off and dropped to eighth.
But it allowed him to pull on the white jersey for three days.
Movistar rider Carapaz kept the overall leader's pink jersey, extending his lead over Italy's Vincenzo Nibali (Bahrain-Merida) and Primoz Roglic (Jumbo-Visma) by seven seconds.
Britain's Simon Yates, the Vuelta a Espana champion, remains eighth, 7min 13sec behind the race leader.
A group of 18 riders had formed a breakaway in an animated start after Tuesday's wet and cold conditions at Mortirolo.
"I focused on Formolo and (Thomas) De Gendt who were the strong men of the breakaway," explained Peters.
"I saw that the others were biding their time and I went for it without questioning myself."
Carapaz put his foot down on the pedal over the final kilometre, gaining seven seconds on Nibali, who he leads by 1min 54sec.
Movistar rider Mikel Landa of Spain also attacked and is now less than a minute behind third-placed Roglic in fourth.
"Mikel Landa felt good in the finale and decided to attack to gain some time for the final podium," said Carapaz.
"I also felt good and I did my best to profit from Mikel's attack. I couldn't have asked for a better 26th birthday than with the Maglia Rosa (pink jersey)."
Thursday's stage offers the remaining sprinters a final chance for a win as the route drops to sea level, with a 222km run through the Venetian hinterlands from Valdaora to Santa Maria di Sala, concluding with a 2km sprint for the line.
The race concludes in Verona on Sunday.