Seahenge (8/1) won the Howcroft Industrial Supplies Champagne Stakes for trainer Aidan O'Brien, ridden by his son, Donnacha and Sky Bet make him a 25/1 chance for the 2018 QIPCO 2000 Guineas at Newmarket.
While Ryan Moore was aboard the shorter-priced Mendelssohn, it was Donnacha O'Brien who landed the Group Two honours on Seahenge, who had only finished fifth behind Expert Eye in the Vintage Stakes at Goodwood.
Dream Today and Hey Gaman were the two leaders until the race got serious in the final quarter mile.
Mendelssohn was one of the first beaten, while Seahenge came with a strong challenge to pip the gritty Hey Gaman by a neck. Mythical Magic was third.
His rider said: "He was very aggressive going down to the start, so I wanted to take my time with him.
"When they quickened from the three I just got caught a bit, but I let him find his feet and when he picked up two out I thought he'd get there.
"My lad will be suited with stepping up in trip again and I think he's a nice horse."
O'Brien said: "Donnacha won his maiden on him at Naas and he was very green. He's a big horse and then he went to Goodwood. Ryan rode him and loved him, but said he was very green and babyish. Obviously he learned a lot there.
"Donnacha gave him a lovely ride today and he came home well. He won very well and you'd be delighted with him. Donnacha went out to teach him a lot and educate him, like we do with all our two-year-olds.
"They didn't go very fast so he did well to win."
He added: "With him we came here thinking he could be one for the Dewhurst and that looks the obvious next step.
"He'll be suited by better ground."
James Tate, trainer of the runner-up, said: "I'm delighted and gutted at the same time, that's what second is all about.
"He's run a cracker and a career-best, but we've just met one that was able to quicken by us today.
"He could try something like the Racing Post Trophy, but that was his seventh run today so I will probably put him away.
"He's just run off 548 Kilos and he's got bigger as the season's gone on. He'll definitely be a better horse next year.
"I nearly didn't run him today as he really does prefer it softer than this. With a horse that likes soft ground, you have one eye on many races.
"He'll never run on ground with the word 'firm' in it and ideally he wants the word 'soft' in it."
