Portsmouth produced a sensational late show to beat Chobham 28-23 in London two south west at Rugby Camp.
The city club trailed 23-15 with just 10 minutes left, but came storming back with a converted try and two penalties to seal the win.
It was a third straight league win, taking Portsmouth within eight points of leaders Sutton & Epsom.
‘From a coaching point of view this is probably our best win,’ said Portsmouth coach Ian Chandler.
‘Our first-half performance against the strong wind was exceptional.
‘We dominated and scored two good tries to get in front.
‘In the second half, a freak try got Chobham back into the game and we were left looking like we could lose.
‘Earlier in the season we might have lost, but we showed our increasing confidence.’
Portsmouth, with Dan Stoneman back in action after missing 10 months with an eye injury, had the better of the early exchanges.
A penalty from full-back Andy Barnes and a try from centre Gareth Richards sandwiched a converted score for the visitors.
Barnes converted Richards’ try but failed to kick the points when full-back Will Carpenter finished off another Richards’ break, on the stroke of half-time.
Portsmouth conceded a try, eight minutes into the second half.
The visitors kicked a loose ball through and a clearance fell to the attacker.
Two further penalties put Portsmouth in deeper trouble but they showed their character from there.
‘Considering we had nine senior players missing it is a terrific win,’ said Chandler.
‘I thought at one stage we might have thrown it away and the way we didn’t give up was pleasing.
‘It shows the depth in the club and suggests that maybe we have finally turned the corner in this league. The win was a real team effort.’
Portsmouth face a tricky RFU Intermediate Cup trip to Charlton Park next weekend.
Their rivals are enjoying a good season in London two south east.