The visitors were outclassed en route to a club record 10th straight defeat in all competitions. Here are our player ratings from South Wales...
1. Lee Burge
His blushes were spared by the sound of the referee's whistle when he spilled a corner under minimal pressure. The fact he made six saves in addition to conceding five goals reflected Cardiff's total dominance, even if most were fairly standard... 5 Photo: Pete Norton
2. Conor McCarthy
Started at right-back but quickly had to readjust and move into a back three as Calderwood attempted to stem the tide. No answer to Cardiff's movement throughout though, especially down his side where they constantly found joy. Played two players onside for the fifth... 4 Photo: Pete Norton
3. Max Dyche
Another one who couldn't handle the slick interchanges and movement of the home forwards. Didn't know if he was coming or going at times as City racked up 25 shots and a massive 48 touches in the Town penalty box. By contrast, Cobblers managed seven touches in the other box... 4 Photo: Pete Norton
4. Jon Guthrie
Rendered helpless as Cardiff ran rings around Town's defence. Was way too easy for the home side to work their way into dangerous positions, and they were also stronger and quicker and could have scored more... 4 Photo: Pete Norton