David Payne has already trained one colt to win a Rosehill Guineas and Australian Derby double and he has Ace High on target for his attempt at the same feat.
Ace High won the Spring Champion Stakes and Victoria Derby Group One staying double for three-year-olds during the spring carnival and he has been building nicely as he has stepped up in distance this time in.
The colt was the $4.40 favourite for Saturday's Rosehill Guineas (2000m) on Wednesday while he is also the favourite for the Australian Derby (2400m) two weeks later which Payne said was Ace High's "grand final".
Payne trained Criterion when he won the Guineas-Derby double four years ago and he said Ace High was looking for the step up to 2000m on Saturday.
"He only started becoming competitive last year once we stepped him up to the 1800 metres and further," Payne said.
"I said to the owner before the preparation, 'we'll only see the best of him at the Rosehill Guineas and the Derby', once he gets up to these distances.
"His runs have been excellent and he's just peaked now, which is good.
"He's nice and fit."
Ace High finished fourth in the Randwick Guineas over 1600m last start and while he couldn't match the acceleration of the winner Kementari, Payne was happy he kept rallying to the line after making a long run.
"What was good about it was he didn't give up and just kept coming," the trainer said.
Rosehill was in the soft range on Wednesday and Payne believes Ace High will be able to handle rain-affected ground and expects him to run well.
"It's a competitive field," he said.
"There's a couple of those New Zealand horses that are unknown, but you've got to take them on and see how good you are."
The Chris Waller-trained D'Argento is second favourite at $5.50 while New Zealand Derby winner Vin De Dance is at $6.
The field includes five of the first six horses home in the New Zealand Derby and New Zealand-trained three-year-olds have won four of the past seven Rosehill Guineas.Mathew Toogood - AAP
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