The colt was on debut for the premiership-winning Waller yard, having performed nicely in two trials prior to his first start.
The son of Zoustar showed a tremendous turn of foot down the centre of the track to win by 1.2 lengths.
Waller stable representative Damien Fitton said the colt just needed time to mature before today's performance.
"He was an expensive colt the Coolmore syndicate purchased," he said.
"We're very privileged to have them in the stable, they've got a lot of nice young two-year-olds and it was nice to see him do that today.
"He just needed a bit of time to mature.
"He's probably taken a bit more time than usual, like most of the Zoustar's do.
"But he's strung together a few nice trials and today was D-Day for him and he got the job done."
"He'll train on enormously from today. He looked a little woolly in the coat, so he's got a lot of improvement to come."
Starman settled toward the rear of the field after jumping from barrier six with James Mcdonald in the saddle.
He was able to get the son of Zoustar to the running rail and track the field into the home straight.
McDonald then moved the colt into clear air with 250m to run, exploding down the middle of the track to pull away and win comfortably.
McDonald, who had trialled the colt in preparation for today's race, said the Waller team have always had an opinion of Starman.
"Obviously he's been held back and astutely placed, so he was here to perform very well," he said.
"He got the firm track that he needs, and he showed brilliant acceleration. (He's a) Lovely Horse.
"To be fair to the staff at Waller's, they've always liked him.
"Dan, who rides most of the babies, he labelled him a pretty good horse right from early days.
"He's just taken a bit of time to come to hand, but they'll be reaping the rewards for sure now."