Broome, left, fends off Lightning Amber© Photo Healy Racing
Broome made all under Donnacha O'Brien to get favourite backers off to a flyer in the opening juvenile maiden on the penultimate day of the Galway Festival.
The son of Australia bounced away smartly and dictated throughout. He was challenged in the final furlong by Lightning Amber (2/1) but readily found more to hold him by a length and a half at 4/5.
Donnacha O'Brien said: "He had a nice run the last day and was still quite green and raw again today but has plenty of ability.
"It's not ideal making the running on a horse that green but with those small fields nobody else was going to go, so I said I'd go myself. This is a nice horse and there is plenty of improvement in him."
This was Broome's second start having finished fifth on debut at Killarney last month.
Aidan O'Brien won this race for the fourth year in a row following on from Amedeo Modigliani last year, subsequent Irish Derby winner Capri in 2016 and Landofhopeandglory in 2015.
Additional reporting by Thomas Weekes
