Brenton Avdulla has shown the measure of his confidence by producing a beautiful ride to guide Allergic to victory at Rosehill.

Avdulla has kicked off the season in sparkling form, with five winners and nine placings from 26 starts.

He sat off the rail on Allergic in third before timing his run perfectly to kick clear in the Premier's Cup Prelude (1800m) at Rosehill on Saturday.

Chris Waller-trained pair Loophole and Marenostro filled the placings.

"I only gave him a bit of a niggle with the hands and heels and he did the rest," Avdulla said.

"He's got a promising future and I'm sure Godolphin are going to have a bright spring."

Trainer John O'Shea said the horse was likely to head towards the Group Three Kingston Town Stakes at Rosehill on September 10.

He indicated there would be more improvement to come from Allergic after two runs into his preparation.

"If you have a look in the enclosure, he's still a good 10 kilos above where needs to be," O'Shea said.

"I think the soft run in transit and a beautiful ride by Brenton offset that."

Avdulla, who has been riding for Godolphin while No.1 rider James McDonald plies his trade in the UK, was narrowly denied a winning double when Sarajevo was beaten a nose by His Majesty later on Saturday.