Gleneagles won the St James’s Palace Stakes and headed a 54-1 treble for jockey Ryan Moore at Royal Ascot.
The dual Guineas winner scored by two-and-a-half-lengths from Latharnach (25-1) to give trainer Aidan O’Brien a record seventh win in the race.
Moore went on to clock up wins aboard Clondaw Warrior and Washington DC.
Solow led a French 1-2 in the opening Queen Anne Stakes, while Goldream held off fellow outsider Medicean Man to land the King’s Stand Stakes.
Buratino was an impressive winner of the Coventry Stakes and is rated a 12-1 chance for next year’s 2,000 Guineas.
Moore clocked up a double when winning the Ascot Stakes on Clondaw Warrior for trainer Willie Mullins, with top jump jockey Ruby Walsh among those celebrating as his wife Gillian owns the horse with a group of friends.
And three-time champion Moore sealed the treble with Washington DC in the concluding Windsor Castle Stakes, bringing up a double for O’Brien.
“He’s the best in the yard at the minute and the best miler we’ve ever had,” said trainer O’Brien after Gleneagles continued his unbeaten run this season.
The son of leading stallion Galileo showed thrilling acceleration to pick up long-time leader Consort.
Latharnach came through to claim the runner-up spot, with Make Believe a long last of the five runners.
Bookmakers claimed they had suffered one of their worst opening days of the meeting – with Solow, Clondaw Warrior and Washington DC joining Gleneagles as winning favourites.