Sinndar's win in the Prix de L'Arc de Triomphe at Longchamp was the fourth by an Irish-trained horse in the race known as the middle-distance championship of Europe. The colt joins Ballymoss (1958), Levmoss (1958) and dual winner Alleged (1977 and 1978) in this exclusive club.

The Aga Khan's colt home-bred, whose dam Sinntara won the Irish Cesarewitch in 1992, has got better as the season has progressed after a hard-fought Epsom Derby win over Sakee in June.

That success, far from knocking the stuffing out of the son of Grand Lodge, had a galvanising effect and, after apparently struggling for a while at the halfway stage, he finished in majestic in his next start, the Irish Derby, winning by nine lengths.

Sinndar was subsequently given a summer break, along classical lines, and trained specifically with the Arc in mind.

An eight-length victory in the most significant of Arc trials, the Group Two Prix Niel at Longchamp last month, showed everything was going to plan.

Sinndar has won seven of his eight career starts - his only defeat coming on his seasonal reappearance at Leopardstown in April when going down by a head to Grand Finale over 10 furlongs. His first Group One win was as a juvenile in the National Stakes and he now has four wins at the highest level.

Labelled an exceptional colt by the Aga Khan, Sinndar deserves every ounce of praise heaped on him. Whereas once he had to grind out victories, he has now added the class to win in style - the true sign of a much improved racehorse.

The Aga Khan, a faithful subscriber to the Arc, had previously tasted success in the big race with Akiyda, but Sinndar's bespectacled trainer John Oxx, a man fabled for his patience, and Johnny Murtagh were hitting the Arc jackpot for the first time.

Oxx's father, John, had trained the 1975 Arc winner, Star Appeal, early in its career before it was exported to Germany.

The Oxx stable had also a Group Two victory at Longchamp on Saturday when Mouramara, also owned by the Aga Khan, was successful in the Prix de Royallieu, worth almost £49,000 to the winner.

With Murtagh in action at the Curragh, Mouramara was partnered by French-based Gerald Mosse.