Australian Guineas hopeful Rock Hero has geared up for his shot at Saturday's Group One feature with a barrier trial win at Cranbourne.

The David Payne-trained Rock Hero won his 1190m trial on Monday by two lengths with race jockey Michael Rodd aboard.

Rock Hero will be joined by his stablemate Criterion in Saturday's $500,000 Guineas (1600m) at Flemington.

"We weren't looking for a time but we wanted to give him a hitout," Payne said.

"He's a big gross horse and needed it. He usually takes a few runs."

Rock Hero finished second as favourite in the Group Two Autumn Stakes (1400m) first-up at Caulfield, won by Thunder Fantasy who is also set to take aim at the Guineas.

The winner of the Listed Dulcify Quality (1800m) in Sydney last preparation, Rock Hero is at $21 in Guineas betting.

Thunder Fantasy is one of three possible runners for Anthony Cummings with Surge Ahead and Alpha Beat in the mix.