Chester:Aidan O'Brien's stable flexed its muscle in the Virgin Money Chester Vase as Ballydoyle's apparent second string Golden Sword cut through the opposition to finish ahead of the trainer's 13-8 favourite Masterofthehorse.
The 25-1 shot, ridden by Colm O'Donoghue, was allowed an easy lead out in front, while Johnny Murtagh was content to sit stone last on the favourite, a fair way off the pace at one stage, and did not make a move until two furlongs out.
By that time Golden Sword had kicked clear of all other pursuers and while Masterofthehorse made rapid headway, he was still two lengths down at the line with Debussy in third.
O'Donoghue said: "He's done it really well, I'm really happy with him.
"He's improved for his first run in France where he put up a good run over a mile and a quarter.
"The step up in trip today suited him well. He's not short of pace, he's a big, strong horse and has got a great action.
"We never underestimated him. He's always shown plenty and we thought he'd be better at three.
"Whatever he did at two he would improve on. I'm delighted and not surprised."
Murtagh added: "I rode him as I was told. In two of his races last year he was ridden handy and didn't finish his races. Aidan (O'Brien) said to drop him in today, let him relax and finish his race.
"Colm nicked three lengths turning in and was able to maintain it, and his horse ran a good race in France last time out.
"I was happy with my horse and the way he finished."
Victor Chandler cut Masterofthehorse to 14/1 from 20s for Epsom but Sky Bet and Hills left him unchanged at 20/1.
Doctor Fremantle got back to winning ways in a thrilling finish to the extrabet.com Huxley Stakes- but only just.
Well-beaten in the St Leger when last seen, Sir Michael Stoute's colt was sent off the even-money favourite to get his season off to the perfect start.
Having swung wide off the bend, Moore appeared to have matters well under control but Walter Swinburn's Staying On, who had cut out most of the running, battled back gamely.
In the middle of the pair was Lincoln winner Expresso Star but as they flashed past the post Doctor Fremantle got the verdict over Staying on by a short-head with Expresso Star half a length away.
Moore said: "It nearly went wrong again! "The lead horse just steadied the pace right up. He (Doctor Fremantle) ran wide off the bend, then when he got to the front he just had a little look.
"I thought I'd held on but the way thing have been going this week I wasn't sure."
Teddy Grimthorpe, racing manager to winning owner Khalid Abdullah, added: "He's got some nice entries. A mile and half will suit him better than that."
Cheshire Prince lived up to his name by landing his fourth win on the Roodee in the Boodles Diamond Velocity Handicap.
Trainer Mark Brisbourne has a great record at the track but appears to target this five-year-old at its unique twists and turns more than any other.
Liam Jones never let long-time leader El Dececy out of his sights whereas Ryan Moore on the 11-4 favourite Kingdom Of Fife was given plenty to do.
Cheshire Prince took over turning into the straight and try as Moore might, the 2lb overweight he put up proved crucial and they went down by a short-head, giving punters a 25-1 shocker.
Richard Hills followed up his win in the Chester Cup with a victory on Fareer in the Boodles Diamond Eternity Handicap.
Close up behind a smart prospect on his seasonal debut, Hills settled the Ed Dunlop-trained 7-2 favourite towards the rear as Goliaths Boy cut out the pace.
The field bunched up as they turned into the straight but Fareer showed a fine turn of foot down the outside and despite hanging to his left causing slight interference, he won cosily from Tartan Gunna by a length and a quarter.