Or do they? Posh were also written off before pulling off these 10 memorable results in knockout competitions.
We’ve rated them in order of shockability, in reverse order naturally...
9. Ipswich 2, Posh 3, FA Cup third round, 1960.
Non-league Posh won at a second Division side managed by future England World Cup winning boss Alf Ramsey (pictured with Bobby Moore) in front of 26,000 at Portman Road. In the following two seasons Ipswich won the Second Division and then First Division titles. Dennis Emery (2) and Jim Rayner scored the Posh goals. Photo: Getty Images.
10. Posh 2, Arsenal 1, FA Cup fourth round, 1965.
It remains the only time Posh have been a top-flight side in the FA Cup after goals from club greats Derek Dougan and Peter McNamee (pictured scoring the winning goal) delivered a come-from-behind 2-1 win. John Radford had opened the scoring for Arsenal.