Cobblers have dropped a place to 17th in Sky Bet League Two following the results of Saturday’s games.
With Northampton not in action due to scheduled opponents Tranmere Rovers playing Tottenham in the FA Cup, other teams around them in the table had an opportunity to take advantage.
Crawley Town were one of those sides to do so thanks to Ollie Palmer’s first-half penalty in a 1-0 victory over Cheltenham, which leapfrogged them above the Cobblers and into 15th.
The gap between Northampton and the play-offs has been extended to 13 points after Carlisle United’s victory over Mansfield, while Town are still nine points clear of the bottom two thanks to a couple of familiar faces as Marc Richards and Jak McCourt scored in a last-gasp 2-1 victory at lowly Macclesfield Town.
There was also frustration for fellow strugglers Notts County, who surrendered a 3-1 lead at Colchester United in a 3-3 draw, while there were wins for Bury over Yeovil and Cambridge against Stevenage. The other match saw Morecambe and Crewe draw 2-2.