Twinlight put up a game front-running display to outpoint his four rivals in the Faber Audiovisuals Ballybrit Novice Chase at Galway.
The Willie Mullins-trained 15-8 favourite was headed just briefly by Argocat at the final fence but he responded to Ruby Walsh's urgings.
Twinlight pulled away on the run-in to score by two lengths. Cootamundra was making eyecatching progress having been held up when he came down at the last.
Walsh said: "He was a bit keen early and recovered well from two mistakes.
"In fairness, it was a good performance and he keeps surprising me."
The jockey honours earlier on the card went to Davy Russell, who netted a near-28-1 hat-trick on Rogue Angel (1-6 favourite), Shrapnel (9-2) and Lastoftheleaders (7-2).