Defeat after a positive display left Tuncay Korkmaz with mixed emotions as he walked away from his role as Deeping Rangers boss.
Phil Stebbing’s double for Peterborough Northern Star ended the hopes of signing off with the Hinchingbrooke Cup before handing over to new manager Michael Goode.
Jordan Avis got a late reply but Deeping couldn’t force a stoppage-time equaliser.
Korkmaz admitted: “We got off to a slow start in the first 20 minutes when they were the better side.
“The difference was that they scored when they were on top.
“We couldn’t capitalise when we finished the first half strongly.
“In the last five minutes Joe Braithwaite had a chance at the far post and Jordan scored.
“But the reality is that we had more possession and they had a striker who looked full of confidence to pick the right positions.
“It’s disappointing to lose but we gave it our best shot and that wasn’t quite good enough.
“I was happy with our performance in terms of having possession.
“This season is the worst finish we’ve had but it has probably been my most enjoyable year with all the young lads who will only get better with experience.
“Michael Goode stayed in the background on Monday but he’s certainly the right candidate for the job. He’s a local lad who knows the club so he ticks all the boxes.
“He is taking over a squad with good players and I hope they stay together.
“I’m leaving with mixed emotions because we lost a cup final but I still enjoyed the season.
“I can’t carry on due to work commitments and in non-League football there are more important things which must take priority in your life.
“But if anyone wonders if I’ll be back in management at some stage then you can never say never!”