Aidan O'Brien was at Longchamp to see Ballydoyle claim the Prix Marcel Boussac and also struck on home soil as Plinth prevailed in the feature Istabraq Hurdle at Tipperary.
After running commendably in defeat in handicap company, the five-year-old was 6-1 to successfully bridge the gap to a Grade Two and got the better of Fethard Player by a length following a duel after the last.
The win was an appropriate result considering Plinth is owned by JP McManus, who also had his colours carried by three-time Champion Hurdle hero Istabraq.
McManus was also responsible for Thomas Edison, but he was a disappointing third as the 4-6 favourite.
McManus' racing manager Frank Berry said: "It was a bit of a surprise and it's great to win. He never runs a bad race and jumped well and kept going. He'll keep running away in those races."
Regarding Thomas Edison, Berry said: "He was disappointing and didn't pick up. "He had a hard old fall in the Galway Hurdle and maybe will get a bit of confidence after that."
Elsewhere on the card, Bachasson had to work a bit harder than expected to justify odds of 2-5 in the Dolores Purcell Memorial Novice Hurdle.
This Grade Three was the next step up the ladder for Willie Mullins' French recruit, who shot to prominence in a couple of the early Cheltenham ante-post markets after scoring at Sligo and twice at Galway.
Ruby Walsh had to get after him to collar Three Stars approaching the last, although he ultimately ran out a cosy four-and-a-half-length winner.
Walsh followed up when The Game Changer (5-2) claimed his second Grade Three prize in the space of a week in the Like A Butterfly Novice Chase, while Mullins achieved a brace of his own courtesy of Prince D'Aubrelle in the Jim Laffan Memorial (Pro/Am) INH Flat Race.
British raider Sovereign Debt denied Dermot Weld his fifth victory in the last six renewals of the Coolmore Home Of Champions Concorde Stakes, but only on the intervention of the stewards.
After tracking the front-running Ansgar into the straight, Tested was asked to go and win her race by Leigh Roche, who left enough in the tank to fend off the Dandy Nicholls-trained 2-1 favourite by a short head, but she was deemed to have caused interference and the placings were reversed.
Seanie hadn't managed to get his head in front since landing the Tote Jackpot Races 3 To 6 Handicap last season, but the 9-2 chance was given a fine positive ride from 10lb claimer Killian Leonard and beat Bubbly Bellini by half a length.
The application of blinkers helped Siamsaiocht (3-1) in the Athassel House Stud EBF Maiden, while 6-1 favourite Phil The Flyer completed a hat-trick in the Woodlands Hotel Adare Handicap Hurdle.
