Jockey Cory Parish will start an 18-day suspension after he rides outsider Cool Chap in the Doncaster Mile at Randwick.

The Racing Appeals and Disciplinary Board suspended Parish on Tuesday for his handling of a horse at Bendigo on February 28.

Bendigo stewards charged Parish following an inquiry into his riding of the Lindsay Park-trained Sonaree in a 1000m maiden.

He was charged with failing to take all reasonable and permissible measures throughout the race to ensure Sonaree was given full opportunity to win or obtain its best possible finishing position.

Stewards said Parish failed to take a run passing the 200m where there was sufficient room and again from the 100m where he made insufficient effort to shift outside the heels of a runner.

They said he also failed to ride with sufficient vigour over the final 100m.

Parish pleaded guilty and was suspended for 18 days to start at midnight on Saturday.

Parish leapt to national prominence when he rode outsider Boom Time to victory in the Caulfield Cup for David and Ben Hayes and Tom Dabernig.

Cool Chap, a last start second to Humidor in the Blamey Stakes at Flemington last month, is also trained by Lindsay Park and drew barrier six in the Doncaster Mile and is at $71.

The Darren Weir-trained Humidor sits on the fourth line of betting at $8 with Godolphin colt Kementari the $3.50 favourite.