Stradivarius produced a scintillating performance to become just the third horse to win three successive Gold Cups at Royal Ascot.
Frankie Dettori bided his time, on rain-softened ground which was thought to be unsuitable for John Gosden's remarkable staying superstar, before closing on long-time leader and eventual runner-up Nayef Road and then streaking clear to win by 10 lengths.
Doubts were sown about the hat-trick bid as rain continued to pour until almost race time - but Stradivarius, in the black and yellow colours he has made famous for owner Bjorn Nielsen, was having none of it.
The six-year-old, sent off as the 4-5 favourite, made those odds look increasingly generous as he settled in midfield behind the pace set by Nayef Road and Withhold and then coasted into a winning position, with Dettori evidently oozing confidence.
It proved well-placed once the Italian crowd-pleaser said 'go' - and Dettori was able to salute the achievement on passing the post in isolation, before then serving up his trademark flying dismount on returning to the winner's enclosure, despite the absence of crowds in this coronavirus-ridden year.
Stradivarius has equalled the achievement of the race's fellow Gold Cup hat-trick heroes Sagaro and Yeats - although the latter still stands alone, having won four in succession for Aidan O'Brien.
Dettori said: "I'm so proud of the horse. He's been a joy to be around. He'll go down as one of the great stayers, like Yeats and Sagaro. Who knows, maybe we'll try for for next year."
He added: "Even with no crowd I'm quite emotional. A very proud moment.
"I was worried about the rain. They were talking up the Martyn Meade horse (Technician) a lot. It was a concern. He actually really surprised me, because he went through it like a hot knife through butter. I had everybody covered. I was surprised I didn't have anyone to challenge me.
"It's always that scary moment when you get to the furlong marker - will he pick up or not - but he did and he stretched away by 10. Amazing.
"We purposely all stayed wide on the fresh ground. That helped a little bit, but nevertheless it was still very soft. It just shows what a fighter and how versatile he is. It's all about Stradivarius today. He's a wonderful horse.
"You're never on the bridle in the Gold Cup a furlong out. Usually everybody labours by the three, so it was an amazing feeling and a fantastic performance. The horse deserves it. I'm very proud of him."
Gosden said: "I'm very proud he's won three and particularly proud for the man who's done it, Bjorn Nielsen, the owner-breeder - he's passionate about breeding and keeps trying to breed a Derby winner, but he's got a very good Cup horse. For him it is profoundly fulfilling and it's just a pity he can't be here today.
"It's down to Bjorn whether we come back for a fourth. We might just look towards the Goodwood Cup next, he's won three of them already, then we might take a pull as there is talk of running in an Arc. He ran brilliantly in the Coronation Cup, so an Arc on Autumn ground isn't out of the question."