Citizen Vic, Willie Mullins' second-string, landed the Dr PJ Moriarty Chase in the hands of Paul Townend at Leopardstown.
With Walsh riding Cousin Vinny, Citizen Vic was sent off at 12-1 and he set out to make every post a winning one.
The challengers queued up in the straight with Roberto Goldback, Zaarito and Weapon's Amnesty all holding chances.
Zaarito crashed out yet again though and it was Weapons Amnesty who gave Citizen Vic the most to do.
However, he never looked like catching the impressive winner and went down by a length and three-quarters.
The winner was cut to 16-1 for the RSA Chase by Sky Bet while Victor Chandler kept Weapon's Amnesty unchanged at 10s.
Mullins said: "He has improved and Ruby recommended stepping him up in trip after he won at Punchestown.
"Paul gave him a lovely ride from the front and he said he had plenty in the locker all of the way.
"I think the Powers Gold Cup at Fairyhouse would be tailor-made for him but we will have a look at the RSA Chase first."
Mullins added of Cousin Vinny: "He jumps too carefully and I'll discuss going back over hurdles with the owners with a view to running in the World Hurdle."
Ladbrokes, sponsors of the latter, gave Cousin Vinny a 33-1 quote for the stayers' event.