Alderwood followed up his victory in the County Hurdle of 12 months ago with victory in the Johnny Henderson Grand Annual.
The victory for Tom Mullins' nine-year-old provided Ireland with a 14th success compared to Britain's 13 over the week; a record number of winners at Cheltenham for Ireland.
Tony McCoy, riding his second winner of the day, gave up the inside to nobody, just like he had done last year, but this time victory always looked likely.
It was a fellow JP McManus runner in Kid Cassidy who was the hare to catch having travelled powerfully throughout but he had no answer to Alderwood up the hill.
The 3-1 favourite won by three and quarter lengths with a former winner in Oiseau De Nuit third and Drumshambo fourth.
Mullins said: "As he'd won last year we always wanted to come back but he was slow to come to hand in the autumn, he just wasn't training properly.
"He was handier last year but we are still a novice so AP gave him a chance. He won easy enough.
"The horse took him along. He's quick, he's brave and he's clever.
"When the rain came it slowed down the rest so it was probably good news.
"To give Ireland the deciding victory of the week, it's probably the first time I've done anything for Ireland in my life!"
