Jessica Marcialis landed a momentous success as Tiger Tanaka won a rough renewal of the Prix Marcel Boussac at ParisLongchamp.
In a real rags to riches story, the filly won three claimers earlier in the season and booked her place in the field when winning a Group Three at Deauville last time out.
In behind Tiger Tanaka there was plenty of trouble in running, with Richard Fahey's favourite Fev Rover done no favours at all before staying on to finish fourth.
Marcialis, who has been making a name for herself in France, was unable to make use of the usual female allowance in a Group One.
But that mattered little on Charley Rossi's Clodovil filly, who powered away to for a memorable success that caped a memorable day for the Rossi family, as his uncle, Frederic, won the Prix Jean-Luc Lagardere with Sealiway earlier on the card.
Marcialis, who is a mother, became the first female to ride a Group One winner in France.
Born in Italy to a racing family, in 2013 Marcialis was Fegentri champion female amateur rider and has worked her way up as a professional from riding in claim races.
She said: "If the filly had come out a little bit quicker out of the stalls, I'd have been able to get a better position, but when the gap opened I had to go.
"It's incredible. I don't have the words. Yesterday we said it was amazing to be here today.
"I want to say to all the mums 'we can do it'. Be strong."
The winning trainer, who was assistant to Criquette Head-Maarek for 10 years, said: "I know what it means to get horses ready for big races, but I don't actually realise yet what has happened and my wife has won this race for me with this filly.
"We bought her out of a claimer for 24,000 euros, but she showed wanted to be with the best and is now the best filly. She is qualified for the Breeders' Cup so why not? And Jessica has won races in America.
"She has a goat in her box and we hope they will be kind enough to invite the goat as well."