They trailed to Matt Saunders’ early try and although Phil Simmons touched down to level the scores with Jack Muggridge’s conversion, Marlow were 15-10 up at the break with Mike Rauchwerger touching down and Will Fulton adding a penalty to his conversion with a Muggridge penalty keeping Blues in touch.
But Marlow scored twice without reply in the second half through Mark Grindrod and Pete Lewis to leave Blues one of four teams at the bottom separated by only four points.