The Celebrity Juice host squared up to the glamour model-turned-bodybuilder in a posedown documented on Marsh's profile.
Some of the pictures show Lemon - the alter ego of comedian Leigh Francis - smothering himself in HP sauce to replicate the oiled-up look Marsh sports in competitions.
The humorous snaps have been published in the run-up to Keith Lemon: The Film's release next week.
Celebrities known to be featuring in the movie include Kelly Brook, Verne Troyer, Lemon's Celebrity Juice co-stars Holly Willoughby and Fearne Cotton, David Hasselhoff and Jedward.
An exclusive Digital Spy clip also reveals that Paddy McGuinness will appear in a scene where he and Lemon visit a lap dancing club.
Keith Lemon: The Film will open in UK cinemas on August 24.
Watch a promo for Keith Lemon: The Film below: