The away side had the better of the opening exchanges and had a few sights of Slough's goal but nothing to trouble Michael Parkin. That changed in the 23rd minute as Adrian Allen found acres of space between Mark Avery and makeshift centre back Ian Hodges to steer home a cross from the left at the near post.
Chelmsford were unlucky not to extend their lead as they dominated the half. Jamie Richards intercepted a Darron Wilkinson headed pass and smashed a dipping volley off the bar with Parkin beaten.
Richards again went close with the opening chance of the second half. Receiving the ball just inside the left hand channel of the area, his low drive was well covered by Parkin's dive to his right.
Slough's first real opportunity of the game fell to Leigh Mason. Leon Woodruffe's low free kick was deflected up and away by the wall. Mark Avery headed the ball back in and it fell through to the run of Mason but Gavin King was out quickly to pressure the midfielder and he could only hook it over the bar.
Chelmsford went close again as Allen beat Parkin to a long through ball towards the left side of the box. The striker crossed to substitute Victor Renner but his low drive was wide. Renner again had another glorious opportunity to add to the score as he was played through the Rebels offside trap. He was indecisive when faced with just Parkin and when he finally got round the Rebels keeper, his sidefooted effort was easily blocked by Andy Ballard who had recovered well to block the shot.
Chelmsford City Line up
Gavin King, Peter Smith, Michael Haswell, Jerrome Sobers, Russ Edwards, Greg Lincoln, Alex Fiddes, Craig Edwards, Jamie Richards, Adrian Allen, Richard Halle, Subs: Michael Gorman, Alex Lawler, Victor Renner, Ronnie Watson, Helder Valdex