Simon Yates admitted he was in shock after bouncing back from his Giro d'Italia "heartbreak" to win La Vuelta and complete a British clean sweep of this year's Grand Tours.
The 26-year-old Bury racer, whose triumph was all but guaranteed as he headed into Sunday's largely processional final stage into Madrid with a one minute and 46 seconds lead, avoided any late mishaps to land his first Grand Tour title.
Victory for the Mitchelton-Scott rider followed success for Chris Froome at the Giro d'Italia and for Geraint Thomas at the Tour de France to round off an unprecedented year for British cycling.
Indeed, it was a moment for the history books, the first year ever the three titles have been held by three riders from the same country.
While Elia Viviani out-sprinted Peter Sagan (Bora-Hansgrohe) to win the 21st stage after a flat 100.9 kilometre ride from Alcorcon, Yates finished safely to retain his advantage over Spain's Enric Mas, Viviani's team-mate at Quick-Step Floors, in the final general classification standings.
And the day belonged firmly to the man in red, who recovered from the bitter disappointment of running out of gas at the Giro after holding the race leader's pink jersey for 13 days to triumph in Spain.
Those punishing three weeks may have ended in agony, but they proved Yates, who won the young rider classification at last year's Tour, had what it takes to contend in Grand Tours - and he delivered at the very next opportunity.
"It feels great, really unbelievable," he said on the Mitchelton-Scott website. "I think it's still sinking in. I have no words, it's just really unbelievable.
"I like to race on my instinct and I hope that I continue to do so and achieve more big results like today at the Vuelta.
"I came back from real heartbreak from the Giro d'Italia and I am still in shock that I've managed to pull it off and it will take a while for it to sink in just what we've accomplished. I get really nervous up on the stage, but it was a very special moment that I will cherish forever."
Julian Dean, the Mitchelton-Scott sport director, praised his rider's "massive progression this year".
He added: "I think even to progress from how he raced at the Giro to here in such a short space of time, is really testament to his willingness to learn. There's still a few things we could improve upon with Simon and, when he starts to understand those things, this kind of result will be repeatable."
Yates' coronation continued Britain's remarkable Grand Tour domination, with Froome's Tour-Vuelta double last year meaning British riders have now won five in a row.
Yates, whose next target is the UCI Road World Championships in Innsbruck later this month, said: "It's astonishing really. Growing up I was so accustomed to seeing the French, Italian and Spanish riders lead the way, so for myself, Chris and Geraint to all win a Grand Tour in the same year just shows how far the sport has come in this country."
Froome paid tribute to Yates' achievement, saying: "Simon has looked so strong over the last three weeks and it's great to see him take home the maillot rojo. It's been a perfect year for British riders."
Sports Minister Tracey Crouch said: "Simon Yates's brilliant victory in the Vuelta is the latest success in a phenomenal year for British Cycling, following on from Froome winning the Giro d'Italia and Thomas the Tour d France.
"It is testament to the talent development programme of British Cycling, backed by National Lottery cash, that so many of our riders have become the world-leading cyclists that they are today. Their success is helping to encourage many more people get on their bikes and get active."