US Navy Flag completed the rare Middle Park-Dewhurst double as his trainer Aidan O'Brien sent out the first four home in this Group 1 score to 24 this year and one shy of Bobby Frankel's record.
Expert Eye, the Qipco 2,000 Guineas ante-post favourite, finished last after getting unsettled in the stalls and racing keenly before drooping away tamely as they raced into the Dip. Andrea Atzeni eased him in the final furlong.
Ryan Moore followed the winning route he had taken on stablemate Kew Gardens earlier in the day – getting the stands rail and making all the running on US Navy Flag.
The War Front colt showed no signs of flagging over the extra furlong after his Middle Park win and matched the feat of winning the two Group 1 two-year-old features at Newmarket last achieved by Diesis 35 years ago.
O'Brien said: "He is a tough solid horse blessed with plenty of tactical speed. He doesn't have to lead and Ryan was happy not to lead but was left there."
As to the double achievement O'Brien added: "It is rare and we are lucky to have a good colt like him who has the speed for six furlongs but looks like he has a good chance of getting a mile – it is exciting."
The stark contrast in the performances of the leading lights brought a landslide change in the ante-post betting for the 2,000 Guineas with US Navy Flag promoted 11-2 favourite by Betfair sportsbook while Expert Eye is out to 12-1 from 4-1 market leader.
US Navy Flag was chased home by Mendelssohn, who carried his owner Derrick Smith's second colours and had tracked him throughout the race with Seahenge staying on from the rear to fill third, just ahead of Threeandfourpence.