Irascible and Dylan Robinson © Photo Healy Racing
The Cashel Maiden Hurdle resulted in a one-two, and a quick double, for trainer Henry de Bromhead.
The 4/6 favourite Decimation was always prominent under Rachael Blackmore and saw off the challenge of Envious Editor after the second-last.
All the while, though, the grey Irascible (18s into 17/2 in late betting) was staying on in the hands of Dylan Robinson and a mistake at the last by the market leader gave him the opening he needed.
The Jukebox Jury 5-year-old, a half-brother to prolific winner Kruzhlinin, stayed on best to win by two and three quarter lengths.
Decimation was second and it was a further eight lengths back to Envious Editor (5/2) in third.
It was a winning racecourse debut for Irascible who finished fifth in his only point-to-point run in March of last year.
Winning trainer Henry de Bromhead said: "They are two nice horses and the winner has always worked like a nice horse. I thought he'd need the run for experience but he picked up really well.
"He was just about ready to run in a bumper when we went into lockdown but he is a great jumper and I'm delighted with that.
"Decimation is a very nice as well and I don't think he did a whole lot wrong to be fair.
They both worked like nice horses and Decimation obviously had the run under his belt and I thought Irascible would need the run and he didn't and Dylan (Robinson) gave him a great ride.
"Irascible could go for a rated novice next and he might even be entitled to go for an open novice but we'll chat to Michael and Eddie (O'Leary) and see."
Additional reporting by Thomas Weekes
