Sosie won the Prix Niel inflicting the first defeat of Prix du Jockey Club (French Derby) winner Look de Vega's career under gorgeous blue skies.
Fabre, who turns 79 in December, may have had eight wins in the Arc but he has only visited the winners enclosure once in the past 18 years, Waldgeist in 2019.
However, the media-shy French handler will be heartened that his Rail Link is the last horse to have done the Niel/Arc double in 2006.
Sosie's jockey Maxime Guyon was in full purring mode about his chances in the Arc run back at Longchamp on October 6.
"He does not do a lot, when he went a length clear he dug his heels in and I had to ask him for more," said Guyon.
"He is able to change gear though, he is very tough a characteristic of Monsieur Fabre's horses.
"He also has a great mental attitude.
"He has shown he is a crack horse and deserves to be the favourite for the Arc."
Only four Vermeille winners in last 40 years have gone on to Arc glory -- Treve the last in 2014.
Whether Blue Stocking makes it a fifth is open to question but the Ralph Beckett-trained filly produced a tough as teak performance to win the Group One race under blazing blue skies.
Rossa Ryan managed to find a bit extra when she was headed by Guyon on Aventure inside the final furlong.
"She was eyeballed by the runner-up," grinned Beckett.
"She was wonderful, I am very proud of her, she is a very tough filly.'Her journey'
Although she is engaged in the Champion Stakes and Fillies and Mares Stakes on Champions Day at Ascot on October 19 Beckett did not entirely discount a tilt at Europe's most prestigious prize.
"Maybe she will run in the Arc now, we could supplement her," said the 53-year-old Englishman.
Ryan, who won on her in the Group One Pretty Polly Stakes earlier in the season, said she had proven herself in being able to adapt to new tactics.
"She adapted really well, she had every chance to lie down when Aventure came alongside her but she dug in for a different gear.
"She is a really genuine good filly, and I am blessed to be part of her journey."
Of the ones that followed her home Aidan O'Brien's highly rated filly Opera Singer was not on tune and finished a well beaten fourth.
The favourite may still get to run in the Arc.
She won the Prix Marcel Boussac at Longchamp last year, and in the eyes of her jockey that day Ryan Moore ticked the boxes as a future Arc contender.
O'Brien's 2023 St Leger winner Continuous's hopes of improving on his fifth spot in the Arc last year took a serious knock when he was a well beaten third in the Prix Foy.
The hot favourite led halfway down the finishing straight and may not have had the race run to his liking.
However, the manner in which he folded to lose to seven-year-old Iresine does not augur well for the Arc in three weeks time.
Iresine, ridden by Marie Velon, has become something of a specialist in the Foy, he also won the 2022 renewal, and was second last year.
However, being a gelding he is barred from running in the Arc and he may yet face Blue Stocking in the Champion Stakes next month.
