SIR Des Champs finally got the better of Flemenstar to claim Grade One glory in the Hennessy Gold Cup at Leopardstown on another incredible day for the Carlow trainer.
Having alerady seen Boston Bob and Champagne Fever claim Grade One glory, Willie Mullins saw his seven-year-old outstay Peter Casey's stable star, who seemingly failed to last out the three miles despite being held up for most of the journey.
The winner's stablemate Quel Esprit, successful 12 months ago, set the pace in a four-horse affair but the race developed into a duel between the big two over the last two fences.
Andrew Lynch hung on to Flemenstar until after the last but he could not quicken to go past Sir Des Champs (11-8), who prevailed by a length and three-quarters.
Earlier, Boston Bob got up in the very last stride to win a thrilling race for the Dr. P.J. Moriarty Novice Chase at Leopardstown.
Willie Mullins' charge looked beaten when he dropped back to fourth after tracking the pace-setting Lyreen Legend but rallied in amazing fashion on the run to the line.
Paul Carberry appeared to have brought Texas Jack with a perfectly-timed run and though he got the better of Lord Windermere and Lyreen Legend, he simply had no answer to the late dash of Paul Townend on the 6-4 favourite.
Champagne Fever had earlier returned to form when making all the running in the Deloitte Novice Hurdle at Leopardstown.
Last season's Cheltenham Champion Bumper winner had run a listless race last time out but Willie Mullins' charge bounced back to his best in this Grade One test.
The 2-1 favourite brushed aside Bright New Dawn, his only serious challenger, and galloped on strongly to the line in the hands of Paul Townend.
The strongly-fancied Waaheb fell at the second flight when at the rear of the field.
Mullins said: "He's back to himself, which is a huge relief after Naas. We just fiddled around a bit with him since then and we waited until this week to give him two bits of work.
"He really impressed in those two bits, especially in his work on Tuesday."
Mullins added of his length and three-quarters winner: "We're always afraid when a horse gets an infection like that which might ruin his season.
"At least he seems to have come back to where he was though.
"It wouldn't be a problem going out in trip with him but we'll stick to the Supreme Novices' Hurdle.
"The plan is that Mozoltov, Champagne Fever & Un Atout will run in the Supreme Novices' Hurdle.
"Pont Alexandre will run in the Neptune and Ballycasey in the Albert Bartlett.
"It will be tough over there, but you send your best and hope that one of them will draw."
Stan James cut Champagne Fever to 16-1 from 33s for the Supreme, and spokesman Joseph Burke said: "It was a pity that Waaheb exited so early, but it was still a very taking performance and he ground out his victory before keeping Bright New Dawn at bay."