Belardo ran out a clear-cut winner of the Dubai Dewhurst Stakes at Newmarket after Andrea Atzeni unleashed his mount with a race-winning move inside the furlong pole.
The Richard Hannon-trained Estidhkaar was the 11-8 favourite following previous Pattern-race success in the Superlative Stakes on the July Course and the Champagne Stakes at Doncaster, but he faced an uphill task after a tardy start.
Belardo, a 10-1 shot after finishing only fourth behind Estidhkaar at Doncaster, was fitted with a hood for the first time by trainer Roger Varian and was well covered up by Atzeni.
He moved noticeably well heading towards the last of seven furlongs, but it briefly seemed he was caught in a pocket.
However, Belardo eventually got the gap he required and quickened up smartly to seal a comprehensive victory by two lengths.
Kodi Bear filled the runner-up spot, finishing clear of Smuggler's Cove in third, with Estidhkaar ultimately disappointing in fourth.
"It's been a great year," said Varian. "Obviously winning a Classic was huge but we've had a few other highlights.
"Cursory Glance (Moyglare Stud Stakes winner) looks top class, and this fellow looks top class, too."
Varian said: "This horse will have confidence going into the winter now. We will now have to dream about the 2000 Guineas.
"It's a lovely way to end the season. You can't come into these races and expect to win because they are so hot.
"On paper, he had to turn round a couple of lengths with Estidhkaar and that one gave us 3lb and a beating at Doncaster.
"I know Andrea thought he'd win that day, but it was a messy race - they went slow and he ran too free, basically.
"Today was a truly-run race. I don't think soft ground is essential but he obviously handles it and he has a very sharp turn of foot, which he showed today.
"He wouldn't need a Guineas prep. He's a very clear-winded horse and a great worker at home.
"We will see. I learned with Kingston Hill that you can't predict your path. No bold statements - options are open."
A clearly impressed Atzeni said: "When I first sat on him I said to Roger that he was one of the best two-year-olds I have ever sat on.
"When I sat on Kingston Hill, he never gave me this sort of feel. This fellow give me the feel to be a top horse and he showed that today.
"I don't know what's behind me, but when I pulled up Adam Kirby (Kodi Bear) said 'that's a proper horse', because I went past his like he was standing still."
Cox said: "He has come here and run with huge credit. I think he will keep us all warm through the winter ahead of next year.
"He has come here 30 kilos heavier than when he won at Ascot and that bodes well for the future.
"As for the ground, he is quite versatile and we can relax in that respect."
Aidan O'Brien's Smuggler's Cove, who bolted up at Dundalk a week earlier, was two and a half lengths back in third.
"The race may have come a bit too soon for him but it was still a good run. That is probably it for the year now and we will get him started back early next season," said O'Brien.
Paul Hanagan told the stewards Estidhkaar hung right during the race, but no abnormalities were found by the vets.
