Posh included five triallists in their side, one of whom scored twice as Posh fought back from 2-0 down. Hamed Ishola netted the winning goal. A triallist also blazed a first half penalty over the bar.
City man Jordan Macleod scored both Spalding goals including a superb individual effort. Spalding are managed by former Posh promotion hero Gaby Zakuani.
Former Posh star Marcus Maddison played for Spalding and was a number of home players to force a decent stop from Posh ‘keeper Dan Gyollai.
Gyollai is back from his trial at Portsmouth who have yet to make him an offer.
Sir Alex Ferguson watched the match at the Sir Halley Stewart Field alongside his son, Posh manager Darren Ferguson.
Posh Under 23 manager Matthew Etherington said: “It is always difficult when you have as many trialists in the side as we had because it does take time to understand each other in how you play, but we were poor and they were told that at half-time.
“In the second half, we got hold of the game, passed it better and those players contracted upped their game and they have to take every opportunity they have because football can be difficult. It was pleasing to win the game, they kept going to the end and they deserve credit for that.”
Gyollai, Aaron Powell, Ethan Bojang (who signed a Posh deal yesterday), Charlie O’Connell, Norburn, Luke Harris and Ishola were the contracted players involved.
A crowd of 1400 watched the match.