Dan Smith’s first half strike was all that separated the sides as the Eastbourne Derby went the way of Town at The Saffrons last Saturday.
The result moves Town up to fourth in the County League division one table while United remain in 11th position, 13 points behind John Lambert’s promotion chasers.
United will feel disappointed not to leave with at least a point from the fixture, but missed chances proved costly for Simon Rowland’s side in the first league meeting between the sides since the 2006/07 season.
An early chance came for Lucas Mann, but Town defender Josh Jirbandey got ahead of the United man to clear for a corner.
On 17 minutes, the only goal of the game came as a weak clearance from Russ Tanner found its way to Liam Baitup, who squared the ball for Smith and slotted in at the far post.
Further chances in the first half were few and far between as the crowd of 408 in The Saffrons were left hoping for better in the second half.
Ten minutes into the second half, Dean Stevens pulled an effort wide from 25 yards as United looked for an equaliser.
Baitup tried his luck from 25 yards for Town, but left Tanner untroubled with his effort.
United’s best chance of the game fell after a driving run and through ball from Bailo Camara found Joe Summerbell, but the young midfielder placed his effort wide of Greg Nessling’s far post.
The final ten minutes saw United push forward, with Camara having a glorious chance to pull United level after outpacing Josh Jirbandey, but his effort again went wide of Nessling’s goal.
A deflected effort from Mike Gardner was gathered by Nessling in the final minute, before United came agonisingly close to securing a share of the points as a goalmouth scramble ended with the ball rebounding off the Town crossbar.
Town: Nessling, Duncan, Henson, McLean, Radley, Jiabandey, Ellis, Darby, Baitup, Smith, Schaaf.
United: United: Tanner, Lewis, Featherstone, Stevens, Davidson, Gardner, Capon, Summerbell, Tate, Mann, Camara.