Talented four-year-old Cluster has continued his march towards fulfilling his Group One potential with a barnstorming win in the Theo Marks Stakes at Rosehill.

One of several horses to join the new training partnership of Peter and Paul Snowden this season, Cluster has gone from a provincial maiden win in June to Saturday's Group Two victory in four starts for the stable.

His former trainer Anthony Cummings thought enough of him to test him in last year's Caulfield Guineas in which he was unplaced.

Senior partner Peter Snowden said Cluster would now return to Caulfield for the Group One Rupert Clarke Stakes on September 28 over 1400m, the same distance as the Theo Marks.

"He had to win today to make sure he got into to the Rupert Clarke," Snowden said.

"That has been the race we have aimed at the whole time."

Sent out the $3 favourite with Tom Clark replacing Josh Parr who was unable to get down to 53kg, Cluster got further back than planned early and was last rounding the turn.

Clark pulled him out wide and Cluster responded to unleash a strong finish, nabbing Bull Point ($3.80) near the line to win by a half neck.

Ninth Legion ($6.50) held his third position another 1-1/2 lengths away.

"He was in the wrong place the whole race which makes his win even better," Snowden said.

"I had a couple of shakes of the head during the race wondering if he could get out.

"I knew if he did he has a massive amount of acceleration which would see him through."

Bull Point's trainer Chris Waller said the Rupert Clarke was also the likely next mission for the four-year-old.

"He will either go to the Sir Rupert Clarke Stakes or stay in Sydney for the Epsom. We're probably leaning towards the Sir Rupert Clarke," he said.

Co-trainer Michael Hawkes said Ninth Legion would head to the Epsom (1600m) on October 4 while fifth-placed Zephyron was on a Caulfield Cup path.