For the third time in less than a decade, New Zealand trainer Murray Baker is taking the Australian Derby trophy home with Mongolian Khan winning the battle of the stayers.

Now the winner of seven of his nine starts, Mongolian Khan has also completed a rare double, becoming the first horse since Bonecrusher in 1986 to complete the NZ Derby/Australian Derby double.

The long-time ruling favourite for Monday's Classic, Mongolian Khan lost favour with punters when he finished out of the placings in the Rosehill Guineas and was sent out at $6.50.

"He is a real 2400-metre horse and just keeps going," Baker said.

"I was very disappointed after the Rosehill Guineas but I knew he would be better over the longer distance as he showed in the New Zealand Derby."

Punters opted to go with the Victoria Derby winner Preferment who was sent out at $3.70 just ahead of Hauraki and Rosehill Guineas winner Volkstok'n'barrell, both at $4.

Outsiders Hampton Court and Brogue led the field with Mongolian Khan and fellow New Zealander Volkstok'n'barrell both tracking the speed.

Inside the final 150 metres, the two kiwis looked set to fight it out but were soon joined by Hauraki.

But under hard riding from Opie Bosson, Mongolian Khan's strength kicked in and he went to the line three-quarters of a length ahead of Hauraki who edged Volkstok'n'barrell by a half head to give Baker a victory to go with his wins with Nom Du Jeu in 2008 and It's A Dundeel two years ago.

For Bosson, who has battled weight throughout his career, the win was sweet.

"I took time off in November to get my focus back," Bosson said.

"I wasn't retired, I was just tired. I'm grateful to Murray and (training partner) Andrew Forsman for putting me on.

"I only got on him because Craig Grylls was suspended and they have stuck with me."

It was the 34-year-old's second Group One victory in Australia with Bosson winning the 1998 Australian Oaks on Grand Archway.

Preferment's trainer Chris Waller said the colt did not handle the heavy track and would be spelled to return in the spring.

Volkstok'n'barrell will return to New Zealand and also be prepared for a spring campaign.

"Mongolian Khan beat us in the New Zealand Derby and our horse just doesn't quite get the 2400 on this ground," trainer Donna Logan said.

Mongolian Khan will also be back for the spring with Baker eyeing the Caulfield Cup.

The colt is owned by the Inner Mongolia Rider Horse Industry, an organisation which has bought around 600 horses in New Zealand of all breeds.

"The owner is keen to win a Melbourne Cup," Baker said.

"I know how good he is over the 2400 metres of the Caulfield Cup but we'll wait and see about the two miles."