Winning handler O'Callaghan, who was born in County Clare and has trained in America since 1990, is also a part-time pub singer in south Los Angeles. He now has his sights set on Royal Ascot.
He said: "I'm Irish through and through, as are the owners, who are from Kinsale, and that's how the horse got his name.
"He's always proved he's a grinder from whatever position he's been in. We'd done all of our homework and I wasn't too worried about the opposition - I only concentrate on my horses. I wasn't watching Rocket Man at the finish, it was my own rocket man I was looking at.
"I knew he had won when I put the saddle on and the race went exactly like I wanted it to. To win here is amazing and is what I always wanted to do with my life. I've now proved I can do it and hopefully it will open more doors. We'll be off to Royal Ascot next for the Golden Jubilee."
Winning handler O'Callaghan, who was born in County Clare and has trained in America since 1990, is also a part-time pub singer in south Los Angeles. He now has his sights set on Royal Ascot.He said: "I'm Irish through and through, as are the owners,