© Photo Healy RacingBrazos was the strongest at the business end of the Portwest Killarney Race over a mile and six.
Shane Foley drove him home by three parts of a length at 2/1.
Constancio (9/4 from 3/1) got up for second from 6/4 favourite Law Girl who couldn't match the winner in the final furlong.
This gave trainer John Murphy a double as he took the preceding race on the card with 33/1 shot Emperor Waltz.
The trainer's son, George, said: "The horses are really starting to come into form and I'm delighted with him.
"He got trapped a little bit at Roscommon and must have come on from it and I think we have an exciting summer ahead of him as he's a decent horse.
"He is a gorgeous, big horse and probably doesn't want really quick ground so that will determine a lot. We'll see what the handicapper does but we've no plan with him."
Additional reporting by Thomas Weekes