Gary Portelli's pet Chihuahua fancies his chances of taking on Sebring Sun but it is a match up of another kind the trainer is hoping the horse can win.

The colt will tackle the Listed Rosebud at Randwick on Saturday bidding to stake his claim for a start in next month's $1 million Golden Rose.

His rivals include Group One placegetter Rageese, the smart Voilier and last-start winner Let's Make It Rain.

But earlier this week it was Portelli's dog who had Sebring Sun in his sights.

"The horse was walking down the driveway to have his afternoon exercise and the Chihuahua was jumping up and down on the fence trying to attack the horse," Portelli said.

"They are not known for their intelligence, Chihuahuas."

Sebring Sun was disinterested in his diminutive challenger but Portelli is banking on the horse entering battle mode at Randwick.

Following a juvenile campaign boasting form around Godolphin's Haptic and Exosphere, Sebring Sun resumed with a fast-finishing win at Canterbury when he came from near-last on the turn.

For Portelli, the victory was a relief, and the confidence-boost he needed to raise the bar.

"I've got no doubt he's up to taking on the best horses around once he learns what it's all about," he said.

"He's got a fantastic turn of foot, he can run fast sectionals but he's still not a tradesman yet.

"(Group winner) Rebel Dane at the same stage was very tractable and easy to ride. This bloke has still got that bit of greenness early in the race. He still wants to go a bit keen and can do a few things wrong."

Portelli sees the Rosebud as an ideal chance to earn the colt some valuable black-type and provide a grounding for bigger targets.

"I'd like to hopefully get this win on the board, get that black type and just hopefully see this horse end up in a Group One and be a legitimate chance," he said.