The final race at Flemington was run in front of packed lawns after a fire alarm emptied the stands.
As the last of the horses was leaving the parade ring, the fire signal sounded around the course.
Patrons on Saturday then had to leave the members and hill stands to the lawns.
James Ross, the Victoria Racing Club's racing development and strategy manager, said the alarm was triggered accidentally, to which the Melbourne Fire Brigade reacted.
Ross said once the alarm had been activated, it was up to the MFB to shut it down.
Jockeys were able to return to weighing area to weigh in after the race, with patrons allowed back into the stands.