Williams said: "It's not a bad 20 minutes to have in any training career. It's lovely to do it on the Flat and over jumps.
"I think he's beaten quite a quality field. I thought he had a lot to do two furlongs out, but Jim has given him a great ride.
"Michael Watts (owner) has been extremely supportive of me and has always given me a chance with decent horses. They are famous colours, so it's fantastic.