Posh were trailing 1-0 when Tayo Edun was dismissed after just 27 minutes leading to a collapse from the home side.
But no damage was done to their survival hopes with Burton Albion, Bristol Rovers and Crawley Town all also losing.
Posh return to action tomorrow night with an interesting pre-cursor to the Wembley showdown when leaders Birmingham City come to town.
So who is going up and down? Here is how a supercomputer – produced by footballwebpages.co.uk – thinks the season will finish.
We’d love to hear your thoughts on this final League One table. Join the debate over on our social media channels.
Get all the latest Posh news each day on our website, here.
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