It was a classic meeting of League Two haves and have nots. Peterborough paraded £400,000 goalkeeper capture Joe Lewis and had £150,000 December signing Ian Hatch on the bench while Macclesfield introduced four loan recruits and four of their substitutes were youth team players.
Incredibly it was Macclesfield, also without 14-goal front line strike-force Francis Green and Martin Gritton, who matched free-spending Posh for football and defended with total tenacity.
Macclesfield could have grabbed a second minute lead with Gareth Evans getting through although Claude Gnapka took a lot of the sting out of the shot to leave Lewis with an easy save.
But on 38 minutes even the 6ft 6in height of the ex-Norwich keeper was not enough to keep out Izak Reid's swirling shot which looked to have taken a deflection off defender Kieran Charnock.
Posh forced the pace before the break and, after Ryan Cresswell had cleared Chris Whelpdale's effort off the line, Aaron McLean sent a low cross shot inches wide before seeing a header from four yards superbly saved by Jonathan Brain.
Macclesfield were reduced to ten men a little more than a minute into the second half when Gareth Evans was shown a straight red card by referee Mike Jones after appearing to plant an elbow into the chest of Lewis.
It was one-way traffic from that point, yet Posh squandered a succession of openings with George Boyd and Whelpdale the most guilty when firing over the bar from good positions while efforts from Whelpdale and McLean were cleared off the line by Luke Dimech and skipper Terry Dunfield.