Notebook caused somewhat of a surprise when coming home in front of the Racing Post Grade 1 Novice Chase in the hands of Rachael Blackmore.
The 7/1 shot kicked for home approaching the straight and kept on gamely on the run-in to see off the challenge of the favourite Fakir D’oudairies.
The son of Samum has now won his last three races over fences having opened up his account at Punchestown in October.
The gelding started his career with hotelier John Nallen when winning his point-to-point maiden at Dromahane before being sold to Mags O’Toole for £70,000 at the Cheltenham Sales.
Winning trainger Henry De Bromhead told RacingTV: "It's what we hoped he might do. He jumped brilliant - he gallops and just loves fences.
"I think it was the first one down the back he took off outside the wings and my heart was in my mouth, but he's quick when he's in close as well.
"They went some gallop and that really suited him. He loves to gallop at speed.
"He can get a bit wound up. I think those two-milers need to be half-cracked to do what they do. They need that bit of madness to jump.
"The Irish Arkle is probably the obvious next one from here, but we'll see what they want to do."
Notebook was cut into 5/1 for the Arkle at the Cheltenham Festival in March.