Cinderford overcame Rosslyn Park by the narrowest of margins to give their chances of avoiding relegation from National One a real boost.
The match was an end-to-end affair throughout with the lead changing hands no fewer than nine times.
Rosslyn Park were looking for the double after winning in London in December and the form book suggested the visitors were the favourites.
The Foresters went into the game having one just one of their previous seven National One encounters while Rosslyn Park had a confidence-boosting five straight wins behind them.
Before the game started there was a minute’s applause in memory of Keith Bell, the founder of the club’s main sponsor KW Bell Group, and a hugely respected figure.
It was the home team who made the best of starts when Sam Smith crossed for an unconverted try after eight minutes.
Park hit back just three minutes later with a try from Jasper Cameron, which Luc Smith converted.
Max Knight restored the lead for the home side with another unconverted try after 18 minutes.
Five minutes later Arthur Ellis put Park back ahead with a try, again converted by Smith.
Back came Cinderford with a try from Tom Knight after 27 minutes, which Jake Shortland converted.
Matt Gordon scored the visitors’ third try after half an hour which was converted by Smith and they went into the interval with a 21-17 lead.
The home team were soon on the attack when play resumed and Paddy Pearce drove over the line within eight minutes of the restart to make it 22-21.
Once again Park responded with a try from Ewan Fenley which Max Craven converted for 28-22 after an hour.
It was all to play for going into the final quarter and Cinderford gave themselves a lifeline when Tom Samak and then Mike Wilcox combined to put Man-of-the Match Joe Mullis through for a try.
Shortland converted to put his team back in front with 12 minutes left and they were able to shut out third-placed Park in the tense closing minutes for a vital victory.
Cinderford now face a must-win trip to bottom side Taunton Titans – who also have hopes of securing their place in National One next season if they can pull off a bonus point win at Veritas Park on Saturday (April 13).
The Somerset side will have been boosted by a 27-40 win over Sale FC in Manchester on Saturday in which they scored six tries.
When the two sides met in December, Cinderford beat the Titans 40-31 running in six tries in the process.
Two teams will be relegated to National Two and Cinderford go into the last round of this season’s matches just a point behind Leicester Lions who are currently safe in 12th position.
The Midlands side face a tricky home tie against Darlington Mowden Park in their final fixture.
Mowden Park are in sixth and will be looking to end their season with a win.
In Counties One Western North, Cinderford United kept their challenge for the title on track, but they had to work hard to overcome a determined effort from Midsomer Norton.
Jack Hall, Tom Reynolds, George Perry and Reuben Hinds scored their tries with Danny Pointon kicking two conversions as United ran out 17-24 winners.
Cinderford (v Rosslyn Park): Cinderford; Mike Wilcox, Sam Smith, Tom Samak, Max Knight, Harry Johnson, Jake Shortland, Tom Knight, Harry Edwards, Nathan Taylor, James Elliot, Tyler Jerrum (capt), Callum Thompson, Paddy Pearce, Joe Mullis, Aaron Ryan.
Replacements: George Porter, Shaun Knight, Jack Shields, George Angell, Jamie Forrester.