Paul Lewis looked to have rescued a point when cancelling out Tobi Sho-Silva's opener, but Jordan Gibson converted from the penalty spot deep into added time. Here are our player ratings from Brunton Park...
9. Mitch Pinnock
He's so often the man Cobblers look to for creative inspiration but even he struggled with his final ball on the day. Was especially frustrating as the visitors found so many threatening positions before half-time... 6
10. Sam Hoskins
One cross-shot flashed past the post and he linked well with Lubala for the equaliser. Bit on the periphery otherwise... 5.5
11. Louis Appere
Slashed at a good chance just a few minutes in before he showed good feet to set up Lewis. But after an influential first-half, he was ineffective in the second and soon made way... 5.5
12. Danny Rose
Swung a volley wide shortly before Carlisle won it... 6