Many fans would have travelled more in hope than expectation given patchy recent results, not to mention Town’s poor record at London Road, but it’s often said that form goes out of the window in a derby and that was certainly the case on this memorable occasion.
Sam Hoskins curled in a delightful opener to get things going before his penalty, which came soon after Tayo Edun's red card, had the Shoe Army dreaming of a first win at London Road since 2006, and those dreams became reality as Dara Costelloe tapped in a third with four minutes of the first half still to play, before Tom Eaves rubbed the salt into Posh's painful wounds by heading in Mitch Pinnock’s late free-kick.
Here are some of the best pictures from London Road...
9. Thumbs up
It was the first time in 19 years that Cobblers fans had seen their team win at London Road Photo: Pete Norton
11. Dara impresses again
The January loan signings have really bought into the club Photo: Pete Norton
12. Edun loses his head
The Posh defender was dismissed for raising his hands to Cameron McGeehan's face during this scuffle Photo: Pete Norton