They were given a huge helping hand when Jack Perkins was sent off after just ten minutes.
Harry Leonard scored a brace either side of half-time to set up what looked like a routine win.
But Posh fluffed their lines defensively allowing Tom Eaves to pull one back and set up a tense finale.
Here are some of the Posh fans who saw the win, through the eyes of David Lowndes. Take a look and see who you know.
Get the latest Posh news, here.

1. Posh 2 Northampton 1
Peterborough United climbed out of the relegation after a nervy win over Northampton Town. Photo: David Lowndes

2. Posh 2 Northampton 1
Peterborough United climbed out of the relegation after a nervy win over Northampton Town. Photo: David Lowndes

3. Posh 2 Northampton 1
Peterborough United climbed out of the relegation after a nervy win over Northampton Town. Photo: David Lowndes

4. Posh 2 Northampton 1
Peterborough United climbed out of the relegation after a nervy win over Northampton Town. Photo: David Lowndes


