The win made it eight games unbeaten for the hostsÂ and kept them in fourth place in the Hampshire Premier League senior division.
Home manager Danny Thompson admitted his promotion chasing side made hard work of it against the bottom team.
He said: '˜I know the conditions didn't help but we were poor in the first half.
'˜The weather proved a great leveller and suited them more than us.
'˜Our opponents were bottom of the league, without a win and had conceded 72 goals.
'˜Our attitude was all wrong because the players thought all they had to do was turn up to win.
'˜Athletico Romsey had nothing to lose and I have been in the game long enough to know upsets can happen.
'˜I warned my players before the game it had nightmareÂ written all over it.
'˜Though we came in at half-time 2-1 ahead we were very lucky to do so.'
It took the home side 13Â minutes to make the breakthrough with a scrappy finish.
Jake Alford saw his first effort hit the bar and when the ball came down he scrambled it home.
The hosts paid for their sloppy display when the struggling visitors equalised soon afterwards.
On the stroke of half-time Jordan Whiteley restored the home sides' lead with a decent finish.
Thompson need to get his players to up their game in the second half.
He added: '˜I gave my players a bit of a talking toÂ at the break.
'˜The first-half performance was nowhere near good enough.
'˜I needed a reaction from them and thankfully they were much better in the second half.
'˜It was one-way traffic and they hardly got into our half.
'˜Our goalkeeper was a virtual spectator.'
Goals from Jamie Hall and Chey Duggan sealed a comfortable win for the hosts.
Thompson wants promotion back into the Wessex League at the end of the season.
Ex-Gosport Borough chairman Iain Sellstrom has come into the club and has already made some significant changes.
Thompson added: '˜We have a new manager's office and new toilet blocks.
'˜There is a lot of work going on behind the scenes to secure the 12-year lease needed to get floodlights into place.
'˜That is needed to move back into the higher level.
'˜On the pitch we are on target to achieve our ambitions.'