Place Du Carrousel (66-1 industry price, 44-1 PMU) caused a huge upset when getting up late to beat Nashwa in the Prix de l'Opera Longines at Longchamp.
Hollie Doyle took the lead early on Nashwa and dictated affairs in the deep ground before kicking clear.
It appeared she had stolen enough ground to hold on but just as John and Thady Gosden’s filly began to get tired, Andre Fabre’s Place Du Carrousel – not seen since finishing a long way behind Nashwa in the Prix de Diane – began to sprout wings.
Fabre said: "The ground has made the difference for her today.
"She won a Group Three and was placed in a Group One but was a bit sore on the summer ground after the Diane and needed a bit of time.
"She's a big, scopey filly and the Breeders’ Cup could now be an option. If not, she will stay in training with plenty of options."
John Gosden said of Nashwa: "She ran a wonderful race. Unfortunately it was tough on her having to go and move across like Tuesday did.
"It cost us at the other end in the final 100 yards."
Mickael Barzalona timed it just right to claim a second winner on the card after also causing a shock in the opening Prix Jean-Luc Lagardere on Belbek (16-1 industry price, 177-10 PMU).
Barzalona's earlier winner stayed on stoutly under a another well-timed ride.
The Andre Fabre-trained colt was always near the front rank in the seven-furlong Group One contest and sat just off the pace, set by Vicious Harry.
Barzalona, winning the race for a fourth time, made his move inside the final furlong and outstayed Gamestop, who had hit the front 200 yards from the winning post.
Breizh Sky finished off well in third, with the Johnny Murtagh-trained Shartash failing to pick up sufficiently in the ground, finishing fourth.
"He failed to settle in his first race but he is a good-looking, well-bred horse." said Fabre.
"Let's see how he is, but I might take him to the Vertem Futurity Trophy at Doncaster. If he ran again it could be there."
Blue Rose Cen (9-2 industry price, 47-10 PMU) was an impressive winner of the Group One Qatar Prix Marcel Boussac.
Trained by Christopher Head and ridden by Aurelien Lemaitre, the Group One event for juvenile fillies was run at a decent clip, and having travelled powerfully in third early on in the two-turn event, she shot clear at the cutaway.
Jim Bolger's Gan Teorainn ran a huge race to stay on nicely to grab second, despite having no chance with the winner.
Aidan O’Brien’s Never Ending Story, who had suffered trouble in running when fourth in the Moyglare, again did not have the best of luck, with Ryan Moore having to extract the filly from a pocket before making her challenge. She quickened nicely when seeing daylight, but having looked set for second, was eventually pipped and settled for third.
"Obviously it’s very important to win a race on a day like this, especially because I wanted to prove to everyone that our yard is capable of winning these kind of races," said Head.
"I have been training since 2018 and at the beginning of this year I received some very good horses, so it’s great that they can now shine on the greatest level.
"This filly won a Group Three here over the same trip and the same ground. This was obviously a step up in class, but everything was going the right way and hopefully she has a great career ahead of her."
The Platinum Queen (9-4F industry price, 7-5F PMU) became the first juvenile since Sigy in 1978 to win the Prix de l'Abbaye.
Second only to Highfield Princess in the Nunthorpe at York, Richard Fahey and owners Middleham Park Racing once again decided to take advantage of the huge weight allowance offered to her as a two-year-old filly.
Hollie Doyle did not blast straight into the lead, but after two furlongs The Platinum Queen was in front.
There were plenty closing in on them as the line approached, with Frankie Dettori leading a small group of three on the near-side rail on Ponttos.
It was Karl Burke’s White Lavender who got closest, with Coeur De Pierre third and Adrian Nicholls’ Mo Celita fourth.
Doyle said: "It's brilliant and great for the owners, who have horses all over the country at home.
"She’s a very quick filly and to win a Group One on Arc day is brilliant. It’s actually my first winner at Longchamp, so it’s great to get that.
"Obviously I just got caught on Nashwa in the race before. Those are the ups and downs, I suppose."
Kinross (11-8F industry price, 17-10F PMU) and Frankie Dettori ran out easy victors of the Prix de la Foret at ParisLongchamp.
Fourth in the race 12 months ago, Ralph Beckett's five-year-old arrived in the rudest of health, having won Group Twos at York and Doncaster on his last two starts.
Back up to the highest level, Dettori was trapped wide through the early stages but the veteran Italian knew what he had underneath him and was happy to take his medicine.
He tracked Fang into the closing stages before being sending Kinross to win the race and the gelding quickened up impressively. Malavath chased him home at a respectable distance but Kinross was in a different league.
Beckett said: "He's bred for this ground, out of a Selkirk mare who loved it, and he came here in a really good place.
"Apart from getting beaten in the Lennox, he’s done it all year. Unless Tenebrism saw out the trip on this ground, I felt he would be tough to beat and that is how it proved.
"It’s great for Marc (Chan, owner) – what a year he’s had, with different horses, not just one.
"He’ll probably go to the Breeders’ Cup Mile now, we’ve always fancied that for him. I’d fancy the Champions Sprint for him as well, but that hasn’t happened for us and we’ll probably go to Kentucky.
"Last year I think we got too far back, Frankie would agree but it doesn’t matter now because he came good today."
