The damage was done in the first half as Maidstone lost at Wealdstone. Jack Cook scored an early opener and Corie Andrews made it two as United were punished for a poor opening 45 minutes.
They improved vastly in the second half, pulling a goal back through Josh Shonibare, but couldn’t find an equaliser. Defeat saw Maidstone move another step closer to relegation, now 12 points from safety, and extended their winless run in the National League to 16 games.
Skipper Jerome Binnom-Williams returned from a calf injury as one of four changes to the side who lost 2-0 at Solihull on Saturday.
There were also starts for James Alabi, Tushaun Walters and Dominic Odusanya, with Kevin Berkoe, Sha’mar Lawson, Mark Marshall and Sol Wanjau-Smith the players to miss out.