Preists Leap provided trainer Thomas O'Leary with his biggest win to date when landing the valuable Ellen Construction Thyestes Chase at Gowran Park.
The eight-year-old finished third in a Grade Three last time but back in handicap company he outstayed his rivals in the prestigious handicap.
Black Apalachi made a bold bit for Dessie Hughes but favourite Newbay Prop appeared to have them all in his sights, travelling well.
However, Preists Leap (20-1) quickened up two fences from home under Philip Enright and the penalty Newbay Prop picked up for winning the Paddy Power Chase told in the final furlong.
Preists Leap went away to win by four and a half lengths from Black Apalachi, with Newbay Prop third and Point Barrow fourth.
'It's one of Ireland's greatest races and I'm delighted to win it,' said O'Leary.
'He wasn't jumping very fluently but I had a word with somebody in eventing who showed me a trick and it improved his jumping in the last 10 days.
'The ground is barely raceable and he loves that and I'm sure he'll win another big handicap. I could say he'll go for the Irish National, but it is likely to be rock hard by then.'