Wins at Lingfield and Ripon, most latterly for the first time over two miles, convinced the Newmarket handler to throw the dice in one of the most keenly contested handicaps of the Flat season.
Trip To Paris (10-1) answered every call under a wise Graham Lee as the Champs Elysees gelding got every yard of the extended two and a quarter miles.
The landscape of the race did not alter too much until the final five furlongs when the front-running Buthelezi faded out of the picture.
John Reel was always to the fore and gained a slight advantage, but Irish duo Quick Jack and Zafayan were hot on his heels and ended up jousting for top honours two furlongs out.
Just when it looked like runner-up Quick Jack had the edge over his compatriot, Trip To Paris, who was hardly well drawn in stall 11, suddenly darted into contention and ended up scoring by three-quarters of a length.
“He’s been a revelation,” said Dunlop. “I’ve always wanted to win this race. It’s very hard to do it, so it’s a great day. I made the strange entry and he’s won. He’s become a man this year.”
Even bigger targets could now be on the agenda, with Trip To Paris now in the frame for the Gold Cup at Royal Ascot and the Melbourne Cup in the autumn.
Lee added a little sheen to his fine afternoon when old-timer Silvanus (25-1) defeated Normal Equilibrium by a length and a quarter in the Merseyrail Day Saver Ticket Conditions Stakes.
Trainer Paul Midgley said: “This has been the plan for a long time.
“He’s in the Dash at Epsom, and I’d say he’ll definitely get in that now.”
Diamondsandrubies earlier bounded into the Classic picture after she dazzled in the Arkle Finance Cheshire Oaks.
The daughter of Fastnet Rock received an accidental crack of the whip on her nose when Ryan Moore went for a winning run, but that did not knock her off her stride as she was six lengths too good for Entertainment.
Coolmore’s UK representative Kevin Buckley said of the Aidan O’Brien-trained 5-4 favourite: “The Oaks is the likely target and she is right in that picture.”
However, O’Brien didn’t have it his own way as Sir Isaac Newton’s Classic aspirations suffered a huge jolt in the Homeserve Maiden Stakes.
The Galileo colt had been trading at around the 12-1 mark to win the Epsom Derby but he could only finish second to Cymro as the 1-6 favourite.
Buckley said: “He’d prefer better ground than that.
“We’ll get him home, see how he is and Aidan can make some decisions.”
Rah Rah (2-1 favourite) snatched victory from the jaws of defeat in the opening Stellar Group Lily Agnes Conditions Stakes.
Owner Dr Marwan Koukash posted a first winner of the week at his hallowed Chester when Lexi’s Hero (10-1) defied fears about the ground to win the Boodles Diamond Handicap.
Not Never remains on the upgrade as he turned the Diabetes UK And British Heart Foundation Handicap into a procession.
Winner of the second of his two starts as a juvenile, the Hugo Palmer-trained gelding returned to action and committed some way from home under Graham Gibbons.
Seeing the extended mile and a half out well, he was eased before the line for a five-length success.