After taking a first-half lead through Charlie MacDonald in the 35th minute Gravesend weathered a response early in the second half from Rovers who did not have enough variety to seriously trouble the Fleet defence.
Early threats from Rovers' Alex Meechan and Bruno Teixeira were dealt with comfortably and the threat posed by Zema Abbey faded as the game wore on as Forest Green fell to their first defeat at Stonebridge Road in four visits.
Jackson fulfilled his moment of destiny in the 65th minute after Danny Slatter had been felled 30 yards from the Rovers goal.
He arrowed the ball goalwards direct from the free-kick and keeper Ryan Clarke barely saw it whistle past him and into the net to easily secure the points for The Fleet.