For the second week running Gosport & Fareham turned a winning position into a defeat - but it will hurt all the more this time as it was their deadly rivals Portsmouth who benefited.
In a game that had all the venom typifying this local derby, the visitors led 14-0 going into the second period against a weakened Portsmouth side.
But, with the penalty count going against them and discipline letting Gosport down, the home side picked their way back into the game after the break.
More and more Gosport became rattled and a couple of key players lost their heads, playing into Portsmouth hands.
A Pete Wylie penalty with less than five minutes remaining sent the partisan home crowd into raptures and their coach Ian Chandler conceded he could not believe his luck.
"We have a lot of injuries this week and Gosport were all over us, so to come away with the win is superb for us."
Promoted from London Division Three South-West last season, Barnes are unbeaten, top of the table and, alongside Richmond, ranked as one of the favourites for promotion having boosted their ranks in the closed season.
But it was only in the last five minutes and a turnover at a scrum that finally took the Surrey high flyers to victory over workmanlike Winchester and coach Mike Marchant was delighted that his side showed their full worth in giving them an almighty scare before going down 25-20.
The only concession that he was forced to allow was that it did not result in a victory for the county capital men.
"What a fantastic performance," he glowed. "OK, we did not bring the points home from it, but we demonstrated that we can more than cope in this division."
Barnes conceded they were fortunate to maintain their unbeaten record.
Andover have picked up their first win - a 23-15 triumph at struggling Cobham to take a step away from the basement of London Two South.
Havant's good start to the season hit the buffers as an injury-ravaged side fell 17-10 at unbeaten Canterbury, a result that drops the Hooks Lane side to fourth in London Division One.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article