With Sakhee, the runaway winner of the Arc 12 months ago, out of sorts Godolphin turned to the fast improving Marienbard to carry their torch. And the 5-year-old did not let Sheikh Mohammed's Dubai-based operation down as he powered through the pack to hold off French Derby winner Sulamani by three quarters of a length.
High Chaparral, successful in the English and Irish Derbies, put up a bold show for record-breaking Irish trainer Aidan O'Brien in third, half a length further back. He was ahead of Califet, who belied his outsider status by running a huge race in fourth just ahead of the first filly home, Islington.
For the irrepressible Dettori, Marienbard's hard fought success was his third Arc win after Lammtarra in 1995 and Sakhee last year.
While missing the outright brilliance of Sakhee, who had memorably demolished his field, Marienbard's win was more the result of earnest endeavor.
Dettori, who treated the crowd of 35,000 to his trademark flying victory dismount, paid tribute to the son of Caerleon who last winter popped up in the Melbourne Cup, where he ran seventh.
"Thank you Marienbard, thank you Godolphin," said the Italian.
"Marienbard is so, so tough, and he's improving. When you get a horse his age who has lots of guts and class it makes them a little special."
Marienbard was earmarked for the Arc, which carried prize money this year of $1.6 million, after a stylish performance in the Group I Grosser Preis de Baden Baden, his second win at that level in Germany this summer.
Out of a Darshaan mare in Marienbad, he is a typical Godolphin pupil - he's been allowed time to develop and mature without being wrapped up in cotton wool.
And Sunday's success looks to have booked him a ticket to the Breeders' Cup in Arlington.
"I've spoken with Sheikh Mohammed," said Godolphin's trainer Saeed bin Suroor, "and Marienbard will probably run next in the Breeders' Cup and then the Japan Cup."
The Turf, at 12 furlongs, rather than the Classic, is likely to be his race at Arlington Park Oct. 26, where he may come up against the two horses immediately behind him, Sulamani and High Chaparral.
Sulamani was the popular choice with the punters and form experts on the strength of his French Derby victory won with his killer turn of foot.
Three weeks ago he had won his prep at Longchamp, the Prix Niel, run at a farcical pace which sparked booing and hissing from the crowd that day.
Trainer Pascal Bary was keen to return to a warmer reception today but it was not to be.
Thierry Thulliez rode according to plan, producing the son of Hernando, also an Arc runner-up, late in the day. Passing Aquarelliste inside the final 200 meters on the outside, the 3-year-old had an answer to everything except his for hisolder foe on the inside in the hands of a man who had almost perished in that plane crash.
The Arc is traditionally no place for the faint hearted, a race which can be as rough as driving around the French capital's notorious 'peripherique' ring road.
But there were no hard luck stories in this 81st renewal.
Islington, representing Sir Michael Stoute, had led the 16 runners into the straight with Michael Kinane on High Chaparral in her slipstream, but Dettori was still waiting to make his move in around eighth.
As they drew level with the stands, Dettori was beginning to weave his magic, and Marienbard responded to his urgings with unfailing determination.
"Five-year-olds are tougher, they can take a fight," Dettori observed.
For all that this age group have a poor record in the Arc. You have to go back to 1988 and Tony Bin to find the last one to hit the target in an event that is more the preserve of the classic generation.
While accepting that their horse would have to put up the performance of his life the Godolphin camp was certainly not running for place money.
Godolphin manager Simon Crisford revealed: "We were sitting in the Hotel Bristol's bar last night and Frankie leaned over and said, 'You know, we can win this race tomorrow.'"
And as history records the Ferrari-loving Italian kept his word.
O'Brien Won't Hold That Tiger
Aside from High Chaparral, meanwhile, Aidan O'Brien may also be represented at the Breeders' Cup by the Storm Cat 2-year-old Hold That Tiger, who ran out the winner of the Group I Grand Criterium 12 months after the seven-furlong test was lifted by a certain Rock Of Gibraltar. Hold That Tiger, a son of Storm Cat and half brother to Editor's Note, circled the field in the straight and nailed Le Vie Del Colon on the wire for owners Michael Tabor and John Magnier.
The all-fillies Prix Marcel Boussac had earlier been won by Six Perfections in the Sulamani colours.
There was no quibbling with the most impressive winner of the day though. That was the Wildenstein family's Bright Sky, who was on a different planet to her rivals in the Prix de l'Opera.
Alec Wildenstein favors bypassing Arlington and aiming the daughter of Wolfhound at Hong Kong in December.
Dettori meanwhile was not the only rider to treat the crowd to a flying dismount.
After the 1000m Prix de l'Abbaye Italian jockey Mirco Demuro tried to touch the stars jumping off the back of his mount Slap Shot.
Hugs and kisses followed with typical Italian exuberance but there was only one small problem. Slap Shot hadn't won.
It took the Longchamp stewards around 15 minutes to annouce the photo which showed that Slap Shot had just been beaten by Continent, trained by British sprint king David Nicholls.
A rather chastening experience but Demuro took it well, saying: "Well it feels like my first Group I winner, even if it isn't."