Darwins Fox battled gamely to open his account in the concluding bumper at Punchestown.
David Roche sent his mount on turning for home in the two-mile contest but he had to work hard to shake off Steele's Rock
13/8f Bishops Walk came wth a late surge but Darwins Fox had enough in reserve to hold on for a neck success.
Winning trainer Henry de Bromhead missed the victory as he was on duty at Cheltenham.
"He was leery in the straight, green, and he kept looking at things. He's a fair horse," said Roche afterwards.
"He was always travelling and Henry told me when I was turning in to get him going. He was right.
"He'll be a fair horse when he goes hurdling. He has jumped at home, not a lot, but he jumps well."