Excelebration easily succumbed to Wise Dan's advances in the Breeders' Cup Mile at Santa Anita on an afternoon of contrasting fortunes for trainer Aidan O'Brien.
Ballydoyle's big hope for the self-styled 'World Championships' could only finish fourth behind the impressive winner, who readily defeated last year's Kentucky Derby hero Animal Kingdom by a length and a half.
O'Brien accepted the residue from his remarkable victory in the Queen Elizabeth II Stakes at Ascot just 13 days earlier had perhaps not been fully erased.
He said: "We felt we had to give it a go, but the edge just wasn't on him today.
"He was very impressive at Ascot, but that was only 13 days ago and it may well have left its mark.
"Joseph (O'Brien, jockey) said that going left-handed first time was also a contributing factor."
Even more disappointing from a European perspective was Moonlight Cloud, who beat just one horse home.
Her jockey, Thierry Jarnet, said: "It was difficult out there - there were a lot of horses moving about early on. She had no speed at the finish."
Wise Dan, conversely, lived up to his Hollywood billing with a ruthless exhibition.
The Charles Lopresti-trained five-year-old had been touted as one of the best milers to emerge from America for some time and emphatically justified the hype.
Wise Dan powered into the lead off a languid pace set by Obviously and eased readily clear of the staying-on Animal Kingdom.
Obviously finished third after a photo-finish with Excelebration.
"He did have a tough race in the Arc on heavy ground and he didn't pick up the way he can do in the straight" - Aidan O'Brien
Such was his dominance, the John Velazquez-ridden Wise Dan broke the one-mile course record at Santa Anita.
Velazquez said: "He's a special horse. He's a pleasure to ride. He lets you do what you want. He's got better with age."
Ballydoyle could not have got off to a better start to the day as George Vancouver gave O'Brien snr back-to-back wins in the Breeders' Cup Juvenile Turf.
The Ballydoyle handler was successful 12 months ago with Wrote, and was this time celebrating in California courtesy of a superb Ryan Moore ride.
Always handily poised, Moore's partner swept into an unassailable position deep along the straight, and had far too many guns for the previously-unbeaten Noble Tune.
Whereas George Vancouver had a dream passage towards the line, the Roger Charlton-trained Dundonnell endured a fractious journey, having raced very wide early on, and finished fourth under James Doyle.
Owner Michael Tabor, of the Coolmore triumvirate, said of George Vancouver: "He's obviously a top-class horse and hopefully he'll go for all the big races."
Charlton was satisfied by Dundonnell's fourth-placed finish.
He said: "He had every chance, but on the day he wasn't quite good enough."
St Nicholas Abbey was an honourable third behind Little Mike in the Breeders' Cup Turf.
Ballydoyle's five-year-old revelled on his return to fast ground, but could not match his heroics of 12 months ago.
Joseph O'Brien's partner galloped on strongly towards the death, but Little Mike, the Arlington Million hero, had already flown.
O'Brien snr said: "He did have a tough race in the Arc on heavy ground and he didn't pick up the way he can do in the straight.
"I hope he will be around and keep going next year."
Fellow Ballydoyle resident Starspangledbanner earlier finished well adrift of Mizdirection in the Breeders' Cup Turf Sprint.
The six-year-old, who returned to action this season after a failed career at stud, set an electric pace but could only finish 10th.
O'Brien said: "Six and a half furlongs may have been a bit far for him. The good thing is that his pace is right back. We can look forward to him next year."
Coolmore can also expect more big days with Shanghai Bobby after he preserved his unbeaten record in the Grey Goose Breeders' Cup Juvenile at Santa Anita.
The powerful Irish owners gained a 50% interest in the two-year-old colt earlier in the week, which looks money well spent on the evidence of this courageous defeat of He's Had Enough.