Elliot Buchanan's stunning strike from 25 yards out on the stroke of half-time proved to be the winning goal, coming just two minutes after former Rebel Leigh Mason had equalised Paul Edgeworth's opener.
Marlow came into the game without a recognised goalkeeper, as regular stopper Luke Blackmore was unable to make it to the game in time. It was left to defender Gavin Lane to don the gloves for the entire game and he did not let his side down.
The game started with a slow tempo, and Dean Clark fired wide after Kyle Jeffrey strode forward from right-back. Leigh Mason, one of five former Slough players in the Marlow starting eleven, hit the target with a long-range effort but it was superbly tipped over by Jamie Jackson.
Marlow gained confidence as the half wore on, and put together a good spell of possession which culminated in another effort from Mason being saved well by Jackson, who dived on the rebound quickly.
Slough’s first real chance came after a neat bit of build-up play between Clark and Herron, and from the winger’s cross, Simon Martin’s header was blocked. Paul Edgeworth, following up, made no mistake and fired into the roof of the net past Lane to give Slough the lead.
Just three minutes later, Marlow were level as Mason coolly slotted a penalty kick past Jackson after the referee had spotted a trip on Yashwa Romeo just inside the box.
Moments before half-time, Slough scored what proved to be the winner via the right boot of Elliot Buchanan. The striker collected a long pass forward, turned in an instant and powered a volley over the head of the helpless Lane.
Slough should have extended their lead in the second half, but Dean Harper headed over from three yards out after Lane found himself in No Man’s Land at a corner kick.
Slough struggled to test Lane thereafter, with Edgeworth skewing a shot wide and Buchanan having a shot cleared away from the line after Lane flapped at another corner.
On the break, Marlow threatened as Mason cut inside and fired straight at Jackson, who was grateful to pick the ball out of the air above his head.
Near the end, a superb last-ditch tackle from Danny Murphy denied Marcus Mealing as he was put through on goal from a long pass.
Marlow Line up
Lane, Case, Elsegood, Roberts, Avery, Gray, Mason, Isaac (Cordice), Stewart, Roche, Romeo (Mealing). Subs not used: Blackmore, Croxford, Stone.