As early as the second minute, United could have taken the lead when Scott Honeyball headed narrowly over from a Phil Mason free kick, which was quickly followed by a goal mouth m?l?e which skipper Mason was unable to convert.
Soon afterwards, Romford hit the bar on one of their few excursions in the home side's half.
The 4-4-2 formation seemed to have settled United and both full backs, Danny Gordon and Danny Honeyball, both had the time and space available to push forward, both taking the opportunity to deliver telling crosses into the box.
Joe and Grieves were combining well and showing signs that the partnership could develop and flourish, as United dominated.
The second period followed the pattern of the first, although United were thankful that Courtnage was alert, as he saved well down to his left, during a rare attack from the visitors.
The impressive Gordon struck a stinging drive which was tipped onto the bar by the equally impressive Romford keeper Jason White, who also denied Hill and Mason from long range.
In the 77th minute, a mistake from Danny Honeyball saw Romford's striker Mbala tuck his chance away well and give the visitors and underserved lead.
Romford could have added a second when the Romford substitute broke clean through following a mistake by Mason, rounded Courtnage, before Clifford got in the block.
The visitors reacted like they had won the league at the final whistle. For the ?smaller' clubs like Romford, a win over ?mighty' Aylesbury is clearly much prized.