Racing at Cranbourne has been halted after the discovery of two holes near the finishing post.
The first three races on Tuesday’s program were run without incident before a tiring Denhill fell in race four, a 1500m Maiden Plate, and apprentice Nathan Punch landed on the ground.
The Victorian Jockeys’ Association said Punch may have suffered a broken collarbone but appeared to escape further injury.
Denhill was uninjured in the incident.
A drainage issue appears to be the cause of the affected area near the winning post.
Cranbourne is scheduled to host another 10 meetings this season, the next a night fixture on March 27.