Cinderford were left to rue their inability to secure a comfortable first half lead in a match dictated by the elements.
The Foresters scored three tries at Silver Leys but the conversion attempts were blown wide and at the end of 80 minutes there was just one point in it.
It was a big match for winger Will Baldwin who was playing in his 50th game for the club.
Mike Austin opened the scoring with a successful penalty after three minutes.
He then scored the first of the visitors’ trio of touchdowns with 25 minutes on the clock to give them a 0-8 lead.
In between the scores there had been several promising attacks but the Foresters were unable to add to their tally.
On the brink of half-time, the home side were inexplicably given the put-in at a five-metre scrum.
Full-back Charlie Parkhouse broke through the Cinderford defence to score and the conversion by Connor Lloyd made it 7-8 at the break.
The Hertfordshire side had the elements in their favour for the second half and were soon pressing forward.
James Ayrton scored a couple of tries, the second of which was converted by Lloyd to give them a 19-8 lead with some 15 minutes remaining.
That prompted a response from the visitors with full-back Reece Dunn scoring two tries in the last 10 minutes to bring Cinderford to within a point..
With just three minutes remaining after the second try, Cinderford could not prevent the narrow reverse.
Cinderford Stags and hosts Greyhound RFC observed a minute’s silence in memory of Barry Roberts, a well-liked member of the Forest club.
The Stags finished a creditable third in Counties Four Gloucestershire North after the 34-24 defeat in Hereford.
There were tries from Joe Freeman, Reuben Hinds, Josh Warren and Jon Jones with Jack Cook kicking two conversions.
Cinderford (v Bishops Stortford): Reece Dunn, Will Baldwin, George Gladding, George Boulton, Will Hendy, Morgan Adderley-Jones, Mike Austin, Harry Edwards, Nathan Taylor, Shaun Knight, Danny Hodge, Tyler Jerrum, Jonny Holliday, George Angell, Harry Hone (capt), Replacements: Tim Brockett, Will Haly, Joe Mullis, Jamie Forrester, Jimmy Williams.