The Cork middleweight takes on rising American star Antoine Douglas for the vacant WBO Intercontinental title in Laval, Quebec, tomorrow live on HBO.
Both boxers were on the scales today ahead of the fight, and both came in within the 160lbs middleweight limit.
First up was Spike, who came in at 158.8lbs – his lightest weight in over SEVEN years.
House fighter Douglas then took to the stage and registered slightly higher at 159.2lbs.
The pair then went face-to-face for the final time before trading punches tomorrow night.
Watch Antoine Douglas v Spike O’Sullivan weigh-in and head-to-head below:
Video courtesy of IFL TV