Stratum Star has shown he is ready for a step up to a middle distance at Group One level with an impressive win at Caulfield.

Trainer Darren Weir was using Saturday's David Jones Cup as a warm to the weight-for-age Mackinnon Stakes at Flemington on October 31.

The $4.40 favourite, Stratum Star didn't let his trainer down in winning by a length win over Awesome Rock ($21) with Leebaz ($8.50) 1-1/4 lengths away third.

Providing Weir and jockey Mark Zahra with a double, Stratum Star was backing up from running third behind Lucky Hussler in the Toorak Handicap last week.

Weir sent Stratum Star to his Warrnambool base after the Toorak placing under the care of Jarrod McLean who reported the gelding enjoyed a great week.

"I thought to give him his best chance in the Mackinnon I needed to run him over 2000 metres and I put my head on the line a bit," Weir said.

"It's great having a bloke like Jarrod for me down at Warrnambool who is a good trainer in his own right.

"He said he'd had a great week and you should be running him.

"That made us confident."

Zahra said he could not have wished for a better run in the race.

"He was all-out on the line but he was backing up and he did have 59 (kilograms) on his back," Zahra said.

Blake Shinn, rider of Fenway, said the mare went from `bolting to beaten' in one stride but felt her action was sound after finishing last while Dibayani locked his jaw and ran off on the turn, putting an end to his chances.