‘I needed to do something really special’

own and got all the way to the finish,” said Kenyan-born Froome, who at one point up the Finestre climb was chased by two fans dressed as doctors and carrying a giant inhaler – a reminder of his ongoing salbutamol case from last year’s Vuelta.

“It was going to take something really special to get rid of Simon, to get away from Tom Dumoulin and Domenico Pozzovivo, and to go from fourth to first.

“I wasn’t going to do that on the last climb alone so I had to try it from a long way back and the Colle delle Finestre was the perfect place – a gravel road that reminds me of the roads back in Africa. I felt good and thought, ‘It’s now or never – I have to try’.”

Froome, who started the day in fourth place in the general classification, three minutes and 22 seconds off Yates, now leads by a remarkable 40 seconds from defending champion Dumoulin of Sunweb.

The four-time Tour de France winner triumphantly punched the air as he crossed the finish line, two minutes and 59 seconds ahead of Movistar’s Richard Carapaz – with Dumoulin fifth – to don the Giro leader’s jersey for the first time in his career. Yates, who began yesterday’s stage 19 with a 28-second advantage over Dumoulin, is now more than 35 minutes off the pace. The Mitchelton-Scott rider, above, fell away as soon as the peloton started up the Colle delle Finestre and could not recover.

A tearful Yates said: “I was extremely exhausted and I gave everything. I’ve not recovered since the [stage 16] time trial.

“There’s been some poker face until today. This was the hardest race of my life but I’ll be back to win some day.”

Froome now has just today’s stage 20 to hold off an inevitable attack by Dumoulin – before tomorrow’s final-stage procession in Rome – and claim the Grand Tour treble of the Giro, Tour de France and Vuelta.

But it will not be an easy task, with the 214km stage from Susa to Cervinia featuring yet another brutal mountain-top finish, as he bids to become the first Briton to win the Giro. “It’s a really hard day,” said Froome, “but the legs are feeling good and I’ve been feeling better and better as this race has gone on, so hopefully we can now finish this off now.”

Sky team principal Dave Brailsford said: “It was probably the best performance of his career and one of the best days in the team’s history.”