Dalasiri's race experience over his rivals proved vital as he provided Barry Geraghty with his third winner of the week in the Louis Fitzgerald Hotel Hurdle.
After landing a huge gamble on his second start Sabrina Harty had thrown him in against some classy individuals where he has come up short.
He looked booked for second again as Gassin Golf, trained by Richard Lee in Herefordshire, swept through to take it up, despite running keen throughout on just his third start over timber.
However, that lack of experience showed at the last where he was slow and Geraghty threw Dalasiri at it and he responded, eventually running out a three-quarter-length winner at 6-1.
Geraghty said: "He looked beaten before the last but he flew that, I thought I was going to get beaten again halfway up the run in but he`s tough as nails."
Harty said: "I thought that whatever he did today he`d come on well over a stone as we were really worried about his fitness as he`d had a bad lung infection.
"He`s bred to stay and he`s a real battler. He might have a break now but we`ll think about giving him a couple of runs on the Flat."
Richard Johnson was left rueing a slow jump at the last on Gassin Golf: "He just jumped it too big and was a bit careful."
Lee said: "If he`d jumped the last he could have won but we were beaten fair and square.
"It was only his third run and he`s still a novice for next season, he`ll need a break but there`s a possibility he could go to Royal Ascot for the Ascot Stakes."