The ultra-consistent son of Bullbars has won 10 of his 22 career starts, including last season's Gr.1 Doncaster Mile (1600m) for trainers Ben and JD Hayes, and following the All-Star triumph he has career prizemoney exceeding A$5.8 million.
Ridden by top-class jockey Luke Currie, who jetted in from Hong Kong to take the mount, Mr Brightside sat midfield for much of the contest and tracked I'm Thunderstruck into the race.
Presented at the right time, Mr Brightside shot to the lead inside the final furlong and won by a cosy half-length from Cascadian in 1:34.47, with The Inevitable running home well for third.
With Ben Hayes in Sydney to oversee the stable's Golden Slipper runners, JD Hayes was the sole trainer on-hand to receive the plaudits.
"It means the world to the family and everyone, the owners, and that was just an experience I've never felt before, so I think it's going to be pretty well celebrated," JD Hayes said.
"Ben is probably wanting to get on the first flight home. This means everything.
"The horse has shown great tenacity from day dot. Wayne Ormond, when he found him in New Zealand, he said that his tenacity to attack the line is just ultra-competitive.
"They are things in champions you can't measure and luckily for us he's just boasting a lot of those qualities."
Hayes felt for injured jockey Craig Williams, who had to forgo the ride due to injury after a fall at Flemington last week, but he was delighted to use his father David's connections in Hong Kong to land the services of Luke Currie.
"Condolences go out to Craig. He did such a good effort getting this horse ready and unfortunately one thing led to another, but that was a 10 out 10 steer from Luke Currie.
"The old man lives three floors up (from Luke) in Hong Kong, so it was pretty easy, we just asked him to knock on the door.
"It was very close between him and Harry Coffey but he rode that an absolute peach and was so confident going into it."
Hayes said Mr Brightside would likely defend his title in the A$4 million Doncaster Mile (1600m) at Randwick on April 1, for which he has been allocated 55.5kgs.
"I think so (go to the Doncaster to defend his title). He'll put himself in an elite bracket, but he's already in an elite bracket in my heart. He's a beauty," Hayes said.
The Kiwi import was originally trained by Ralph Manning in Cambridge, for whom he ran a luckless fifth in his sole New Zealand start at Matamata before being sold privately to clients of the Hayes stable via Australian agent Wayne Ormond.
Manning and good friends Shaun Dromgool and Ray Johnson purchased Mr Brightside as an unraced two-year-old off gavelhouse.com for just $7,750, with some insight into the youngster.
Johnson, with his late wife Martha, had bred and sold the son of Bullbars as a yearling at the 2019 New Zealand Bloodstock May Sale for $22,000 via Janine Dunlop's Phoenix Park before he had failed to meet his $50,000 reserve when re-offered at the New Zealand Bloodstock Ready To Run Sale.
Later an opportunity arose to buy him back off online auction gavelhouse.com and despite being aware the horse had a few tricks, Johnson jumped at the opportunity to buy back in.
Out of the Tavistock mare Lilahjay, Mr Brightside is a half-brother to Will Power, an eight-time winner in Hong Kong.Lilahjay is in turn out of the Keeper mare Keepable, a half-sister to multiple Group One winner Foxwood, who is the dam of Group Three winner Rockwood.