In a year of outstanding milers Palace Pier propelled himself right into the heart of the argument with a hugely taking performance to dismantle a high class Jacques le Marois field.
In doing so he rounded off a perfect weekend for Frankie Dettori, who can enjoy the delights of Normandy this week without fretting about his decision to forego York's prestigious Ebor meeting.
And for John Gosden there is the satisfaction in repeating the famous victory of Palace Pier's sire Kingman here six years ago, both superior milers whose class overcame the worst of the drenching to which Deauville can be prone in the summer.
Forced by quarantine regulations to watch on television from home, Gosden was unable to judge underfoot conditions for himself but was in no doubt as to the magnitude of Palace Pier's effort.
"It's much deeper than in Kingman's year, he's never seen anything like it," said Gosden. "He's never even worked on soft ground. It was a bit of a shock to him.
"He's impressed me with his courage. I know he's got a bundle of ability but fully at the 600 metres where they join the main track I saw Frankie’s hands having to nurse him and I thought 'uh-oh'. I said to Rachel 'he's hating this ground' and I don't think he liked it one bit. But he just showed a lot of class and guts to get the job done."
With Alpine Star and Circus Maximus rounding out a stellar 1-2-3 it is Mohaather that now lays in Palace Pier's path to undisputed number one in the mile division, a rival he seems sure to cross once if not twice before the end of the season.
Gosden said: "We've got to be thrilled with him and I'd just love to see him back on good to soft. The big target with him now is the QEII.
"I don't see him as a Breeders' Cup Mile horse, I really see him as a mile or mile-and-a-quarter horse. I'm not sure about the tight turns of America. My question is rather does he go to the Moulin or not and then it will definitely be the QEII. Quite frankly after that I'd like to put him away for next year.
"I haven’t had great experiences with the turf course at Keeneland and it cost Golden Horn."
Dettori was similarly smitten with a colt that is now five wins from five starts, and who belatedly started his season at Newcastle before turning into a Group 1 winning machine.
"I know he's got that kick but when I got to the 600 [metres] I still had three good horses a good three lengths in front of me," said Dettori, who was winning a fifth Marois. "I didn't want to give him too much to do so I said to him 'come on, let's lay up'. And within 300 yards I was two lengths in front, which just shows you how good he is."
Dettori added: "I was concerned about the ground but he dealt with it. I like his temperament and he's very cold, nothing fazes him.
"He's very switched off and he's got some gears. For a horse that's only run five times you've got to be very taken because that was a great field of horses and he's never met competition like that."
Dettori admitted that he has been surprised by Palace Pier's emergence given his demeanour this spring.
"I rode him in the spring and we were trying to make him into a Guineas horse but we couldn't get him to pick the bridle up, he was so laid back," said Dettori.
"John was brilliant because he sent him to Newcastle and it woke him up. It gave him lots of confidence, he came back a different horse and that's why we went to the St James's Palace. All of a sudden the switch came on and we knew we had a good horse on our hands."
Alpine Star was among the first to be asked for his effort by Stephane Pasquier but responded with every ounce of talent in her small frame to be a clear second, while Circus Maximus ran another commendable race in third.
Both carry the colours of the Niarchos family [Circus Maximus is owned in partnership with Coolmore] and racing manager Alan Cooper reflected: "The ground was difficult for everyone, for the first, second and the third. Obviously everyone would have preferred better but that's what we’ve got on the day and there are no excuses from us.
"Circus Maximus is a very tough horse and his record in top races is exceptional. It looks like they are a very good crop of three-year-olds. Alpine Star really got her second wind but the best horse won.
"I reckon in principle Alpine Star could go for the Prix de l'Opera and we’ll have a think with everyone about Circus Maximus."
Persian King was three lengths further back in fourth while defending champion Romanised looked a real threat two furlongs out but was unable to accelerate out of the cloying turf.
"I'm very happy with the run," sad Billy Lee, who must now complete his own two weeks of quarantine on returning to Ireland. "He travelled lovely and I was going as well as Frankie down to the two pole. I thought we were going to be a good third but it was a long last furlong for me on the ground."