Any lingering doubts trainer Mick Price had about Tarzino not handling the clockwise direction have been erased in emphatic fashion in the Rosehill Guineas.

The Victoria Derby-winning colt stamped his authority on Saturday's Group One race early when Craig Newitt put his mount in a handy position out of the barriers.

As I'm Belucci ($41) assumed the lead, Newitt kept the $3.10 favourite in touch and ready to pounce.

VRC Oaks winner Jameka ($8) strode to the lead in the straight but the staying powers of Tarzino kicked in and cruised past her with Montaigne ($6.50) chasing on the inside.

In the end Tarzino was a comfortable 1-3/4 length winner over Montaigne who edged Jameka out of second by a long head.

"It's his first time in Sydney and there's always a doubt," Price said.

"I thought it might have been a bit of a bogey day for him.

"But he showed what a really good stayer he is.

"If he goes to the Derby in good order they won't beat him."

Newitt agreed, saying the colt could only improve over the 2400 metres of the ATC Australian Derby on April 2.

"When he gets to the Derby distance he will be even better," he said.

"He is an out-and-out stayer and fast becoming one of the best horses I've ever ridden."

Tarzino has consolidated his position as the Derby favourite at $1.90 ahead of Friday night's Alister Clark Stakes winner Tally at $6.

Jameka is at $8 and Montaigne $11 with trainer Anthony Cummings and jockey Blake Shinn believing he too can only improve.

"I think with a more even speed over 2400 metres he will be better suited," Cummings said.

"He's got a better finish apart from at least one horse there today.

"We are in the game."

Jameka's trainer Ciaron Maher has not ruled out the filly running against the colts and geldings in the Derby.

"We had the favours in the Vase at Moonee Valley when she beat Tarzino and he had the favours today," he said.

"She is still in the Derby and there is every chance she could go there."