His first strike was the pick of the bunch when he jinked his way through the Eoin defence before blasting to the net on his way to a memorable afternoon during which he tallied 4-4 (0-2f). Team-mate Greg Murphy accounted for the remaining three points.
For Costello, yesterday's impressive display came fast on last week's semi-final performance when he scored 3-8 as Ardscoil saw off the challenge of Castleknock Community College at the home of Ballymun Kickhams, Páirc Ciceam.
At the break, the Marino boys led by 3-5 to 0-3, with the midfield partnership of Gavin Burke and Tommy Byrne providing the platform for their dominance.
However, in the second period the Booterstown school posed far more problems for the Ardscoil defence and battled bravely to the final whistle. Ardscoil had to thank a stout defence where Martin Moore and Conor Mullins, nephew of the legendary former Dublin midfielder Brian, were particularly strong in their six-point success.