Corker Hill, noseband, comes to head Ripples Effect© Photo Healy Racing
Corker Hill came with a sustained challenge in the last two furlongs of the mile and a quarter handicap to get up and win at 25/1.
The five-year-old mare was sixth turning into the home straight but began to stay on strongly and moved into third a furlong and a half from home.
She maintained the gallop and collared 6/4 favourite Ripples Effect with 200 yards left. The runner-up kept on but had no answer to Corker Hill. Eighteen Summers who led throughout, finished third at 14/1. He was beaten five and a half lengths by the winner.
Handler Noel Lawlor said: "I'm delighted for Derek as he's a big part of the team along with Rory (Cleary). He gets on great with her. She's a bit temperamental but when she's in the humour, and things go right for her, she's a serious filly.
"I've been swimming her lately at the Curragh pool and it seems to have settled her. I've only four horses in training but things are going pretty well."
Additional reporting by Alan Magee