The opening twenty minutes or so were pretty even, with Warren Harris unlucky to see a shot from the edge of the area fly just wide from Simon Dunn's pass, whilst City striker Tunde Adewunmi was unlucky on a couple of occasions - first putting an effort wide from close range, and later firing wide after doing well to muscle his way through down the right hand side.
Adewunmi had another effort comfortably gathered by Scott, but there were signs that Slough were gaining the upper hand.
James Dobson fired a 19th minute free kick into the defensive wall, but made no mistake from another free kick from a similar distance eight minutes later. An error from City defender Charlie Day led to the goal, as he lost possession and then fouled Gavin James on the edge of the box. Dobson stepped up, and this time curled hit shot over the wall and beyond the despairing hands of Enol Ordonez to give Slough the lead.
Slough grew in stature as a result, and in truth never looked back. Gavin James was thwarted twice by an Ordonez save and a defensive block, but the Rebels' second goal arrived on 36 minutes. A ball over the top found Lee Barney, who raced onto it and got in a shot across goal which was parried by Ordonez, but only as far as James, who took a touch and poked the ball into the net.
City started the second half looking to reduce the arrears, and attempted to bolster their attack by introducing Cemal Ramadan and Giovany Lopes.
But whilst the home side did well to contain Slough, they still looked to have a lack of a cutting edge in front of goal, and their best effort was a long-ranger from from Ramadan that was comfortably held by Scott.
Slough looked for a third, with Harris controlling a Dobson long pass and shooting wide, and later a superb bit of interplay between James and Barney almost set the former clean through, but Ordonez raced out to collect.
The Rebels were comfortably on their way to victory when the third goal arrived three minutes from time, and it was James Dobson again who provided the finish. He cut in off the wing before thrashing a shot past Ordonez at his near post.
The home side got on the scoresheet in the final minute following the award of a penalty against Brad Hewitt for a handball offence. Adewunmi stepped up and sent Scott the wrong way to deny him a clean sheet and record a consolation goal.
Cambridge City Line up
Enol Ordonez, Paul Cooper, Charlie Day (c), Harry Norman, Jordan Williams, Jack Uttridge, Dean Mason, Erkan Okay, Tunde Adewunmi, Charlie Woolfe, Conor Loker. Subs: Cemal Ramadan, Alex Serrano, Giovany Lopes, David Femiola, Neil Midgley.