Bluestocking ensured she repaid connections when battling on strongly to land the Qatar Prix de l'Arc de Triomphe at Longchamp on Sunday.
Following a hard-fought success over the same course and distance in the Group 1 Prix Vermeille, connections of Bluestocking decided to stump up the €120,000 fee to supplement their filly to Europe's premier middle-distance event.
The daughter of Camelot was sent off a well-backed 5/1 chance in her bid to claim a third top-level prize after landing the Group 1 Pretty Polly Stakes earlier in the season, and those supporting the renowned green and pink silks rarely had a moment of worry, as she enjoyed a trouble-free passage in the slipstream of Los Angeles.
Ryan Moore attempted to kick from the front on Los Angeles, but as Aidan O'Brien's colt began to falter, Rossa Ryan sat ready to strike at the two-furlong marker. The Ralph Beckett-trained four-year-old filly hit the front with purpose entering the final two furlongs and although Christophe Ferland's filly Aventure, who chased her home in the Prix Vermeille, attempted to get on terms in the closing stages, she was never able to get by.
Los Angeles galloped on well to finish back in third for team Ballydoyle, with market leader Sosie claiming the fourth spot for Andre Fabre and Maxime Guyon.
It was a record seventh Arc for the late Khalid Abdullah's famous racing operation Juddmonte.
A delighted Beckett said: "It's a tribute to her constitution as much as anything. It's extraordinary to have a horse to start in May and dance all those dances, the King George, the Juddmonte (International), and get beaten and come back and do that.
"After only three weeks and what looked like a tough race in the Vermeille, it's extraordinary. She is an extraordinary beast.
"I think the draw helped; it was terrific. He got her into the right place, and everything went to plan, he was able to pull it off.
"Westover hit the front with a furlong left last year and I was kind of waiting for something else to come and get her, what a day.
"This is our best ever day, it has to be. I've been lucky enough to win a couple of Oaks, but this is our best day, for sure.
"Barry Mahon and the Juddmonte team are an extraordinary outfit to work for in that there is no pressure, ever.
"Good horses train themselves. Amazing, really. I never thought she'd win."
A jubilant Rossa Ryan told Equidia soon after passing the line: "I know everyone overlooked her, but on form, she had been at the top table and done it all. She just proved she's something else.
"I can't really believe it; this filly has been something else to my career.
"My family are here; they all came over and it's very surreal."
Mahon, European racing manager for Juddmonte, said: "It's absolutely amazing, the job Ralph has done with this filly all year has been unreal. It's unbelievable, what a filly.
"That's Juddmonte's seventh winner in the race, I think that makes them the winning-most owner of all time so that's a special record.
"It's a brilliant day. She had a perfect trip the whole way round, Rossa had it all planned in his head. He was going to be handy; he had a lovely trip the whole way and at the top of the straight I thought it was going to take a good one to beat her."
