The Saints were quick off the blocks in front of 9,000 strong home crowd, former England wing Jon Sleightholme taking advantage of some fine interplay between team-mates Ben Cohen and Oriol Ripol to crash over for a try after two minutes.
Fly-half Paul Grayson was on hand with the conversion as Northampton took the game by the scruff of the neck, dominating play with some muscular moves that left a number of Wasps struggling.
Wasps’ key men Rob Howley, Simon Shaw and Craig Dowd were all forced off for medical attention in the opening quarter, inevitably causing some disruption in the visitors’ ranks.
But after re-adjusting to their new personnel, Wasps came back into the match with No.10 Alex King kicking a penalty.
Northampton struck back immediately through Mark Connors try and then Paul Grayson in the 23rd minute.
The half finished at 15-6, with a front rower from each side cooling their heels in the sin bin after a flurry of punches at a scrum.
After the break, Northampton upped the tempo of their game, Grayson kicking two early penalties to stretch his side’s lead.
Wasps hit back through a try from Josh Lewsey – converted by King – but Northampton were too disciplined to allow a late fightback by the visitors and a late try from Wales lock Steve Williams sealed the result for the Midlanders.
For Northampton Saints:Tries: Mark Connors, Jon Sleightholme, Steve WilliamsPens: Paul Grayson (5)Cons: Paul Grayson (2)
For London Wasps:Tries: Josh Lewsey, Kenny LoganPens: Alex King (2)Cons: Alex King (2)