JAMES McDonald said The Autumn Sun would only get better after the valuable colt left a Caulfield Guineas field in his wake on Saturday.
The Chris Waller-trained colt raced away to a four-and-a-half length win in the Group 1 race, which carried a $2 million purse.
Sent out the $1.75 favourite under James McDonald, The Autumn Sun defeated outsider Vassilator ($101) with Oohood ($9.50) a long-head away third.
"He's going to be scary in the autumn as he's still a baby," McDonald said. "I don't know how Chris does it all the time, but he's been planning this race for two months.
"The horse came here for the first time and got around like a dream."
Waller will leave a decision on whether The Autumn Sun takes on champion stablemate Winx in the Cox Plate to the owners, Hermitage Thoroughbreds and Arrowfield Stud.
But it would be his recommendation to bypass the contest and be content with victory in a race that fast-tracks a winning colt to a lucrative stud career.
"He's a very good horse and I don't think he's fully mature yet, Waller said. "I still think he's going to fill out a lot more.
"He'd have to be the world champion if he was to beat Winx.
"If he wasn't to be a world champion in two weeks' time, he certainly will be in six months' time.
"I'm a punter at heart. I'm addicted to the sport and he's one of those horses that make you go, 'Wow, how good is he.'"
Waller said in the long term he would like to travel abroad with The Autumn Sun after not having that opportunity with Winx.
McDonald said it was pleasing to finally get back on the board as a Group 1-winning jockey after spending 18 months sidelined through suspension.
He said it wasn't the plan to ride The Autumn Sun in the manner he did.
"It's been a frustrating day and it didn't go to plan," McDonald said. "I wanted to be three-wide, with cover but he jumped too well. "He was first out, he's never done that in his life and that was the undoing of my position.
"I was worried. I could feel the punters hands tightening around my neck."
Veteran Caulfield trainer Colin Little backed his judgement and was rewarded with a second placing for Vassilator.
"We targeted this race so it was a good result. His run the other day took a bit of the wind out of our sails when he put his head up in the air," Little said.
Little said he made a few gear changes to Vassilator and told jockey Beau Mertens to give him plenty of galloping room.
"He beat the rest. It was a great effort," Little said.
"I'll go home and think about his next start. He'll get more ground. He's in the derby but I might try and give him a 2000m run and then put him out for the autumn and Sydney as he likes wet tracks."