Tyler Wright’s deflected drive made the difference as Pinchbeck United finished the season on a high.
With just five minutes to go, his shot went into the bottom corner of net via defender Ashley Coddington.
The match-winner should probably be classed as an own-goal but Wright got the benefit of the doubt, although his effort appeared to be off target.
There was confusion at the end as well when Ben Allen was dismissed just before the final whistle for violent conduct.
Moulton Harrox team-mate Bobby Patterson was then shown a red card after the game for foul and abusive language.
The Premier Division champions had missed out on a double as Pinchbeck beat them for the second time in the past month.
Unfortunately, Friday’s final failed to live up to the expectations as these rivals managed more cards than clear-cut chances.
The opening period lacked quality and it didn’t get much better after the break.
Tom Brooks, Liam Ogden and Tony Edwards had gone close for Pinchbeck while at the other end Ian Bradbury offered the only threat from Moulton.
Joe Townsend tried to break the deadlock but Ian Dunn’s shot was blocked, Edwards’ cross bounced off the bar, Ogden fired wide and Coddington’s last-gasp tackle denied Edwards.
After Pinchbeck took the lead, there was still time for player-boss Dunn to go close twice.
He beat goalkeeper Lee Kenealy outside the box, only for Phil Grove to clear off the line.
The on the counter-attack, Dunn’s drive was tipped over by Kenealy.
Allen was sent off for a wild kick as Pinchbeck tried to play out the final seconds near the corner flag and they were soon celebrating.
4-4-2: Kenealy; Groves, Coddington, Patterson, Johnson; Townsend, King, Watkin, Allen; Bradbury, Panton. Subs not used: L Steadman, Lambe-Hyner, Clay, Maltby.
4-4-2: Ashton; B Murrell, A Murrell, Withers, Gardner; Wright, Bishop, Brooks, Ogden; Dunn, Edwards. Subs not used: Leggett, Saebe, Brown, Francis, Dickinson.
Wright (85 mins, 0-1).
Allen (violent conduct); Patterson (foul and abusive language).
Edwards (dissent); Dunn (diving); A Murrell, Allen (fouls); Watkin (kicking ball away).
Liam Ogden – always offered an attacking threat in a game which lacked real quality with so many average performances.