A home tie with Doncaster Rovers or Accrington Stanley awaits the winners after substitute Emmanuel Fernandez saved the blushes of goalkeeper Nicholas Bilokapic to rescue a draw.
Photographer David Lowndes took these pictures of some of the fans at the game.
Take a look and see if there is anyone you know.
Get the latest Posh news each day, here.
13. Posh 2 Salford 2
Peterborough United fans watch their side struggle to a 2-2 draw at home to Salford. Photo: David Lowndes
14. Posh 2 Salford 2
Peterborough United fans watch their side struggle to a 2-2 draw at home to Salford. Photo: David Lowndes
15. Posh 2 Salford 2
Peterborough United fans watch their side struggle to a 2-2 draw at home to Salford. Photo: David Lowndes
16. Posh 2 Salford 2
Peterborough United fans watch their side struggle to a 2-2 draw at home to Salford. Photo: David Lowndes