Hong Kong-based Australian jockey Zac Purton headed to Japan this year on a mission to find the Melbourne Cup winner.

That's how he secured the ride on Admire Rakti, the new Melbourne Cup favourite after a barnstorming Caulfield Cup win on Saturday.

He had never met Admire Rakti's owner Riichi Kondo or trainer Tomoyuki Umeda.

Purton knew the strength of the Japanese stayers and was only too happy to accept the ride on the seven-year-old in the Melbourne Cup and as well as his lead-in run in the Caulfield Cup.

But a trip to Melbourne last week to partner his Cox Plate mount Sacred Falls in the Caulfield Stakes had Purton thinking he could snare the Caulfield Cup.

Purton went to Werribee and galloped Admire Rakti and felt the entire was sharp enough to win over 2400m.

"I specifically went to Japan in the off-season to try and pick up a ride in the Melbourne Cup," Purton said.

"That was my goal and obviously I have done very well but it's not over yet.

"The stable had me believing that he was going to be better at Flemington.

"He races better second-up, but after I rode him in work last week and felt how sharp he was I thought I would win this race."

Purton was in a relaxed mood after another big win in Australia racing.

He returned from Hong Kong during the Sydney autumn carnival, partnering Sacred Falls to victory in the Doncaster Mile but Purton took the Caulfield Cup victory in his stride.

"It doesn't matter if I'm riding for the biggest owner in the world or someone who has a $1500 horse," Purton said.

"At the end of the day I've got a job to do and I've got to do it for whoever I ride for."