Found has led in a stunning trifecta for champion trainer Aidan O'Brien in Europe's most prestigious race, the Prix de l'Arc de Triomphe, at Chantilly.

Although he has won most of the world's biggest races, O'Brien admitted the achievement was probably the finest moment of his career after the mare beat Cox Plate placegetter Highland Reel and Order Of St George.

"It's a privilege to be here and be part of it," O'Brien said.

"How can you see anything higher than this?

"I couldn't dream this would happen. You know how difficult the Arc is.

"And what makes it amazing is that they are all by Galileo."

Despite having defeated previous Arc winner Golden Horn in America last October, and being unfortunate not to be much closer than ninth in this race 12 months ago, Found had unsettled many punters with her five consecutive second placings.

The perception of her wide draw being troublesome soon subsided as Ryan Moore was nicely pitched in eighth place as Vedevani, a pacemaker for dual Derby winner Harzand, led the charge around six furlongs (1200m) from home.

But it was within the final 250 yards that things began to get serious for Found, who shot clear.

Highland Reel gave chase with honourable vigour under Seamie Heffernan, but he was never going to catch his stablemate, who was 1-3/4 lengths clear at the line.

Order Of St George was another 1-1/2 lengths away.

Trainer Roger Varian admitted he was disappointed by Postponed, the 15-8 favourite, who could only finish fifth.

"It's a feeling of disappointment as we went in hoping we would win, but the main thing is we still have a horse to go to war with and we can take him home and see how he comes out of it.," he said.

Harzand was unable to challenge and finished ninth while Japan's wait for a first Arc continues with Makahiki never a factor.

Typically, the Coolmore camp was reluctant to map out an immediate game plan for Found, although part-owner Micahel Tabor said the Breeders' Cup Turf at Santa Anita will be discussed.

But as Moore, in his own round-about way, was keen to point out, this was an occasion that should be savoured without the need for future stargazing.

"To saddle the first three in an Arc, and to get three horses there in top shape and beat the best around, is quite incredible," he said.

"She was in her best shape today and things worked out, back to a mile and a half (2400m) and a nice, evenly-run race.

"She showed what she is capable of - at her best she is a very hard filly to beat."