However, before that, Star Boy will head to Grafton for the Listed Ramornie Hcp (1200m) following his win in the Shorty Cribb Aberdeen Cup (1280m) at Muswellbrook on Sunday.

Thirty-five minutes earlier Star Boy's half-brother, Boom Gate, won the Snowden Racing Class One and Maiden (1750m).

"The Ramornie and the Kosciusko have always been in the back of my mind for Star Boy but he needs to win the Ramornie first," Cavanough said.

"I thought this horse would be in top company by now but foot issues held him back.

"I still think that eventually he will get there.

"He is only a four-year-old and has only been lightly-raced because the owners have been so patient."

Keagan Latham settled Star Boy ($1.70 favourite) in third place, just off the speed, went to the lead half-way down the straight to win by one-and-a-half lengths from the $12 chance Cascata Rossa (Jenny Duggan).

Last Saturday Cavanough was doing his nominations for next month's Grafton carnival but when it came to the Grafton Guineas, he did not have a suitable horse.

Twenty-four hours later he found a Guineas runner in Star Boy's half bother Boom Gate, which could not have been more impressive in winning at only his second start.

Boom Gate went into the race after running third in a 1600m maiden at Moree three weeks earlier.

"We always thought he would be a stayer, so I will give him a freshen up and he will go into the Guineas without another run," Cavanough said.

"It is three weeks to the Guineas so it fits in perfectly."

Duggan let Boom Gate ($18) drift back to third last before working forward towards the turn, hooking to the outside in the straight and motoring down the centre of the track to win by a long neck from the favourite Bellum.