A superb finish from Galvin helped the Gordon Elliott-trained seven-year-old claim the Savills Chase at Leopardstown.
In a thrilling finish, Davy Russell steered Galvin home in first.
A Plus Tard - with Rachael Blackmore aboard - looked set for victory, but was pipped at the line.
Kemboy finished in close third.
A Plus Tard had set out as favourite, with Galvin setting off at 7-1.
Brilliant persistence from @_Davy_Russel_ as Galvin denies A Plus Tard in defence of the @SavillsIreland Chase @LeopardstownRC pic.twitter.com/YfoaR8J1m2
— Horse Racing Ireland (@HRIRacing) December 28, 2021
Russell - who only returned from injury in September - was delighted with the result.
"It's great to do it on the big stage," he said.
"I've had a few near misses but hadn't won a Grade One since I came back.
"I wasn't sure where the line was as I had my head down and my saddle slipped a little bit.
"I knew the further away the line was, the better chance I had. Gordon has done an outstanding job and has nursed him [Galvin] along."
Elsewhere at Leopardstown, Klassical Dream held off the challenge of Flooring Porter to take the honours in the Christmas Hurdle.
Paul Townend was on board the Willie Mullins trained horse to secure victory.
At Limerick, Sean O'Keeffe and Concertista combined to land the Grade Two Mares Novice Chase.