Always held in the highest regard by his trainer Ed Walker - who took the brave decision not to run in the Diamond Jubilee at Royal Ascot when the heavens opened - the Duke of York Stakes winner went off 9/2 here and looked like he had a bit to do over a furlong out.
But once meeting the highest ground, jockey Tom Marquand's mount found overdrive to beat favourite Dragon Symbol and defending champion Oxted by a length and a quarter and a short head in this famous Group One sprint.
Art Power, who had blazed a trail on the far side, was just behind in fourth place.
Walker, saddling his first Group One winner, said: "It's great. It's taken its time, but better late than never as they say.
"I always believed so much in this horse. I put a lot of pressure on myself and it's great that belief has been vindicated.
"His only blip was on bad ground at Ascot last season and we've been proved to have made the right call in missing the Royal meeting.
"I hoped he'd win a Group One and we dreamed that he'll be a sprinter of a generation.
"A horse that was going through the grades as quickly as he was, you have to dream."
While normally unwavering in his faith of his stable star, Walker admitted to having some pre-race doubts ahead of his latest assignment.
"He was so professional at York and today I was really negative before the race. He was messing around (in the pre-parade ring) and if you'd spoken to me then I'd have been pretty doom and gloom," the trainer added.
"You always dream with a horse like this. They're all champions when they walk into the yard, but this horse has never let us down."
The Lambourn handler has another smart sprinter on his hands in recent Group Three winner Came From The Dark, but he does not anticipate the pair locking horns.
A potential next port of call for Starman could be the Betfred Sprint Cup at Haydock on September 4.
Walker said: "Came From The Dark has to avoid this guy. In my mind, they're not in the same league.
"He's a very good horse Came From The Dark, but this guy has that brilliance. Came From The Dark has got guts and battles it out.
"I think Came From The Dark is more of a five-furlong horse whereas with this guy, it looks like six is the absolute minimum.
"We'll look at the Sprint Cup and the Prix Maurice de Gheest."
Oisin Murphy, who had steered Starman to victory at York, was this time on board Dragon Symbol.
First past the post in the Commonwealth Cup at Royal Ascot before being demoted to the runner-up spot after he was found to have interfered with American challenger Campanelle, Archie Watson's charge again had to make do with minor honours.
Murphy said: "I'm thrilled for Ed Walker. I was given the choice and I picked the wrong one, but I'm thrilled for their team and they're having a fantastic season.
"I hope Dragon Symbol will get his day, we could well look to France next potentially for the Prix Maurice de Gheest."