Murray Baker is an old hand when it comes to winning the Australian Derby but for his young training partner Andrew Forsman, Jon Snow's win is a whole new world.

Baker, who previously won with Nom Du Jeu (2008), It's A Dundeel (2013) and Mongolian Khan (2015), stayed at home in New Zealand on Saturday and let Forsman take the glory after Jon Snow slugged out a tough win.

Sent out at $7.50, Jon Snow tracked race leader Harper's Choice ($26) from the outset with the latter belying his price to keep running strongly into the straight.

The pair went stride for stride until Jon Snow got the upper hand to win by three-quarters of a length.

Hardham ($31) finished another short head in third, with the favourite Gingernuts ($2.60) fifth.

"It's a pleasure to be in partnership with a great trainer. He's a master and knows how to bring them over here and get the job done," Forsman said.

"He knows how to get them fit and ready and I'm just glad we pulled it off."

Jon Snow finished third to Gingernuts in the New Zealand Derby in March, with the former scoring an Australian Group One win in the Rosehill Guineas two weeks ago.

The path for Jon Snow was to run in last week's Tulloch Stakes (2000m), which he won to get him ready for the 2400 metres on Saturday.

For his jockey Damian Lane the Derby was his first Group One win in Sydney and one to savour, with his father in the crowd.

"It's a great thrill to win a Derby on such a seasoned horse," Lane said.

"Murray Baker has been a great trainer over many years now and Andrew does a great job as well.

"To be able to have a ride for them and win two good races in two weeks is a privilege and a credit to the horse."

He switched off outside the leader beautifully and when I switched him back on at the 600 he came up under me nice.

"It was almost a replica of last week. Jason Collet rated the leader beautifully and I was able to sit a length, length-and-a-half off and switch him back on at the 600 and it was all business from there.

The runner-up's trainer, Gerald Ryan, was proud of Harper's Choice, as was his jockey, Jason Collett.

"He had a soft lead with no pressure," Collett said.

"He managed to figure in the finish but was just out-toughed by the Kiwi horse."

Baker's son Bjorn is a successful Sydney trainer and had Impavido in the race after having Jon Snow as his guest for the past couple of weeks.

"It's a proven formula to send the horses over here to my stable," he said.

"It's just a shame my horses can't do as well. Impavido finished 10th."