Tuncay Korkmaz was left disappointed by the second-half display which saw Deeping Rangers throw away an advantage.
They went ahead through Spencer Tinkler’s penalty just before the break but Newport Pagnell Town hit back to take three points back to Buckinghamshire courtesy of Josh Crawley and Jared Cunniff.
Deeping boss Korkmaz said: “It was a contrast between a good second half last week and a bad second half this week.
“We got on top of Saturday’s game and played some decent football on a difficult pitch.
“If anything we probably thought another penalty call was clearer than the one we got.
“We deserved to come in 1-0 up but you can’t plan for what happened in the second half.
“There were too many poor performances and we made a mistake for their first goal. It was given away and that was a huge difference at the wrong time.
“It gave them some mom-entum to put us under the cosh. If you can’t win, you need to make sure you don’t lose it.
“Our players dropped their heads and couldn’t get going again.
“Full credit to Newport Pagnell, though, for hassling us, forcing mistakes and asking questions.
“We will take the positives from the first half and learn the lessons from the second half.
“We tried to play on a heavy pitch but sometimes you need a plan B to get the best out of the team.
“Once the surface cut up it became a more physical game and they dealt with it better than we did.”