Given a fine ride by Gerald Mosse, the 43-10 chance got the better of a tussle with Dream Well, last year's Irish and French Derby winner, to score by a head, with Croco Rouge, who had to squeeze through a narrow gap at the two-furlong marker, a length back in third.
Sagamix, the Prix de l'Arc de Triomphe winner and a hot favourite yesterday, suffered the first defeat of his career in fourth place, a further six lengths adrift. The ground, officially good to soft, was deemed too fast for Leggera, who was withdrawn by John Dunlop.
"Dark Moondancer is in the Coronation Cup and Grand Prix de Saint-Cloud," de Royer-Dupre said, " but his next race could be the King George."
Plans were also being made yesterday for Worldly Manner, despite the disappointment of his seventh place in the Kentucky Derby on Saturday. The sole Godolphin challenger after the eve-of-race defection of Aljabr, Worldly Manner travelled easily at the top of the home stretch, but faded as the D Wayne Lukas-trained winner, Charismatic, went for the wire.
Godolphin's racing manager, Simon Crisford, blamed lack of stamina for the colt's defeat. He then nominated the Preakness Stakes at Pimlico a week on Saturday, at nine and a half furlongs just 110 yards shorter than the Kentucky Derby, as Worldly Manner's objective.
"He obviously had a lot of daylight all the way round, but when he hit the straight the trip was too far for him," Crisford said. "He ran a big race, but the last furlong found him out."
"The horse was very fit. He'll stay in America and we'll try for the Preakness."
Aljabr, unbeaten in three starts in Europe last year, including the Prix de la Salamandre, was scratched after injuring himself in work.
(1m 2f Grade One Kentucky Derby, 3YO)
1. CHARISMATIC (C Antley); 2. Menifee; 3. Cat Thief. 19 ran. Nk, 3/4. (D Wayne Lukas). Pari-Mutuel (includes $2 dollar stake): Win 64.60; places (1 & 2) 27.80, 8.40. Show (1, 2 & 3) 14.40, 5.80, 5.80. Non-runner: Aljabr.
(1m 2f Group One Prix Ganay)
1. DARK MOONDANCER (Gerald Mosse); 2. Dream Well; 3. Croco Rouge. 5 ran. Sagamix (4th). Hd, 1, 6. (A de Royer-Dupre)
Pari-Mutuel (includes one franc stake): Win 5.30; places 2.90, 2.00. Straight forecast 29.70.