The 2014 Cheltenham Gold Cup winner Lord Windermere finished third on his season bow as Don Cossack claimed the John Durkan Memorial Punchestown Chase.
The 13-8 winner, ridden by Brian O'Connell, took the lead two fences out and won by four-and-a-half lengths from favourite Boston Bob (11-10).
Don Cossack's trainer Gordon Elliott said: "They all came to beat him, but he picked up and galloped to the line."
RaceBets quote Don Cossack at 8-1 for Cheltenham's Ryanair Chase in March.
|BBC racing correspondent Cornelius Lysaght|
|"A most encouraging return by Lord Windermere. The defence of his Cheltenham crown next spring is obviously the main thing, and trainer Jim Culloty had indicated in recent days that the horse's condition would benefit from having this run.|
|"So, supporters can be pretty happy: having jumped well, behind but in touch with the leaders, he stayed on strongly to grab a close third late on."|
It was Don Cossack's second Grade One win after victory in the Drinmore Novice Chase last year.
Elliott added: "I'll have to talk to owners Michael and Eddie O'Leary, but if I had my way he wouldn't run until Cheltenham and go straight for the Ryanair.
"He's always had plenty of stick and people have said he's been disappointing, but he's a dual Grade One winner now."