It was the second time in a matter of days that Posh have conceded three goals at home following the Boxing Day defeat to Mansfield.
Our photographer David Lowndes took these pictures of some of the Posh fans who were there. Have a look and see who you know.
Get more Posh news each day on our website.
1. Posh 1 Barnsley 3
Peterborough United slipped to another home defeat as their struggles go on. Photo: David Lowndes
2. Posh 1 Barnsley 3
Peterborough United slipped to another home defeat as their struggles go on. Photo: David Lowndes
3. Posh 1 Barnsley 3
Peterborough United slipped to another home defeat as their struggles go on. Photo: David Lowndes
4. Posh 1 Barnsley 3
Peterborough United slipped to another home defeat as their struggles go on. Photo: David Lowndes
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