Chris Froome charged into the overall lead of the Giro d'Italia with a stunning solo ride to win stage 19 while former leader Simon Yates slid well out of contention.
Team Sky star Froome attacked with 80km of the demanding 181km stage from Venaria Reale to Bardonecchia left and won by two minutes and 59 seconds from Movistar's Richard Carapaz.
Froome, who started the day in fourth place in the general classification, three minutes and 22 seconds off pink, now leads by 40 seconds from defending champion Tom Dumoulin.
Froome said: "I don't think I've ever attacked with 80km to go like that before on my own, and got all the way to the finish.
"But the team did such a fantastic job to set that up for me. It was going to take something special to try and first of all get rid of Simon, to get away from Dumoulin and (Domenico) Pozzovivo and to go from fourth to first.
"I tried to stay within my limits and stay within myself, so hopefully we can finish this off."
If Froome's win was one of the most emphatic of his career, there were reminders of the ongoing controversy generated by his adverse analytical finding for Salbutamol at the 2017 Vuelta a Espana.
At one point as he struck out alone, Froome, who has spoken openly about his need to control his asthma, was pursued by two spectators dressed as doctors and carrying a giant inhaler.
Froome is bidding to hold all three Grand Tour titles at the same time, following on from his fourth Tour de France crown and La Vuelta win last season.