Boston Bob was made to pull out all the stops by You Must Know Me on his fencing debut in the Irish Stallion Farms EBF Beginners' Chase.
Willie Mullins' Boston Bob, second to the ill-fated Brindisi Breeze at Cheltenham in March, is already one of the favourites for the RSA Chase back at Prestbury Park.
Sent off the 1-5 favourite, Ruby Walsh was content to let Henry de Bromhead's You Must Know Me have an easy lead, but approaching the third-last Walsh was asking Boston Bob to get a bit closer.
Into the straight Boston Bob appeared to make the ground up easy enough but You Must Know Me would not lie down and in the end Walsh had to work as the odds-on shot prevailed by just half a length.
"It was harder than I expected this morning, but not harder than I expected after I'd gone down to the start" - Ruby Walsh
Walsh said: "It was harder than I expected this morning, but not harder than I expected after I'd gone down to the start.
"It was heavy at Cheltenham yesterday but not as bad as that.
"I was delighted with the way he jumped as for my money he'd been a bit careful at home, but today he was brilliant.
"Three miles will probably bring out the best in him. We've always thought he was a hell of a good horse.
"He's had a good start, a good clear round and he's won."
Mullins said: "He made hard work of that and his jumping probably kept him in the race. He wasn't impressive anyway.
"We'll see how he comes out of the race, but he won't be going to Leopardstown (at Christmas).
"It might take him some time to get over that so we won't make any plans at the moment."