Castlereagh Kid continues to repay the faith shown by Gai Waterhouse and John Singleton with the front-running three-year-old bringing up a winning hat-trick in the $300,000 Group 2 Autumn Classic (1800m) at Caulfield.

The Hall of Fame trainer revealed post-race that selling the son of Snitzel had been discussed prior to this campaign, but they decided to give him one last preparation to prove himself.

Castlereagh Kid responded with a first-up eight-length win in a 1600m Gosford maiden, followed that with a gutsy benchmark 64 win over 1800m at Sandown before his Caulfield success, which took his record to three wins from five starts.

“I was talking to ‘Singo’ and six months ago and if he didn’t have his act together in the autumn we were seriously thinking whether we should sell him or not because he was a he was a bit of plodder, but he’s gone from an ugly duckling to a beautiful swan,” Waterhouse said.

Similar to Sandown, Castlereagh Kid ($4.20) was under pressure early but responded in the straight to score a 1-1/4-length win over Lucky Decision ($6) with $3.80 favourite El Patroness, who travelled wide and laid in in the home straight, a half-neck away third.

Damien Oliver has been aboard for Castlereagh Kid’s two Victorian wins and endorsed him an Australian Derby (2400m) prospect, which is where Waterhouse and her co-trainer Adrian Bott will direct the son of Zabeel mare Absolute Joy, who is a half-sister to Sunday Joy and Tuesday Joy.

“He’s a unique horse,” Oliver said. “He does feel like he’s a genuine stayer.

“What I really like about him is when he’s challenged halfway down the straight that he seems to find a second wind and go again which is an unusual quality for an Australian-bred horse.”