It was the sixth time the Godolphin trainer has saddled the winner. African Story (12-1) had not looked an obvious contender, but was ridden perfectly by Silvestre de Sousa to wear down the front-running Mukhadram half-way down the straight.
The 12-1 chance stretched well clear by the line. Investec Derby winner Ruler Of The World, uneasy in the betting and with a poor draw, struggled from some way out under Joseph O'Brien.
It was a landmark moment for De Sousa, who said: "He was very unlucky here last time when he banged his head in the stalls, but he has proved he's the boy. It's an amazing feeling, one of absolute delight. Godolphin called me to ask me to join their team and I was privileged to accept.
"Saeed thought African Story was a great horse. He had a couple of issues, especially on his second start this year, but tonight he was at his absolute best. In fact, I had to pinch myself because of how well he was travelling."
Japan had a fine meeting with Ryan Moore keeping his cool to guide Japanese mare Gentildonna to victory in a rough Dubai Sheema Classic, and Just A Way (3-1 favourite) proving in another league in the Dubai Duty Free.
Moore won the Japan Cup on Gentildonna (4-1) and last year's runner-up, trained by Sei Ishizaka, moved well but appeared to get cut up by Cirrus Des Aigles when about to make her move and needed to be snatched up for another effort. She got her head in front, and quickened past the French veteran inside the final 100 yards. Roger Varian's Ambivalent collected third.
Mike de Kock's Mars suffered an ultimately fatal heart attack in the early stages. As Richard Hughes tried to pull him up, he crashed into the rail and threw the British champion jockey. Luckily Hughes was only left winded with cuts and bruises.
Just A Way earlier stretched six-and-a-quarter lengths clear of Vercingetorix in an astounding track-record time.
The big disappointment was John Gosden's The Fugue, the Irish Champion Stakes winner struggling from some way out, while Sir Michael Stoute's Dank stayed on for third.
The Fugue eventually finished 11th and Gosden said: "She has run a bit flat and I think we'll wait for Royal Ascot now."
Jamie Spencer had an epic night, helping 33-1 chance Certerach cause a big upset in the Dubai Gold Cup, then pairing up with Jamie Osborne's horse-of-a-lifetime Toast Of New York in the UAE Derby. Toast (11-1) was not the most fashionable of runners, but drew two-and-a-half lengths ahead of Asmar.
At Doncaster, Ocean Tempest was a shock 20-1 winner of the William Hill Lincoln. The five-year-old grey held off the persistent challenge of the well-fancied Tullius (7-1 joint-favourite) to land the first big race of the Flat season by a length-and-three-quarters. Robert The Painter (25-1) was third and Sweet Lightning (11-1) fourth.