Northampton recovered from the Anglo-Welsh Cup loss to Exeter with a bonus point win over a battling but outgunned Dragons side at Franklin's Gardens.
Saints only led 12-0 at the break after wing Juan Pablo Estelles and hooker Reece Marshall crossed -- with fly-half Stephen Myler converting Marshall's touchdown.
But they eased to a 41-7 victory with tries from wing Ken Pisi, scrum-half Cobus Reinach, back row Tom Wood and replacement scrum-half Alex Mitchel, with Myler kicking two more conversions and a penalty and replacement stand-off James Grayson kicking one conversion.
Estelles finished off a great move after 10 minutes involving full-back Harry Mallinder but the Dragons battled back, put Northampton into their own 22 for a period and gave the home side something to think about.
Centre Rory Hutchinson should have scored on the left but knocked on a pass from lock Michael Paterson with the try line begging.
It was backs to the wall stuff from the Dragons as the half ticked down inside the final 10 minutes and only handling errors prevented the Saints from grabbing a second try.
The Dragons' staunch defence creaked and eventually buckled when Marshall grabbed his first try for Northampton with a dive around the corner of a ruck near the posts, which made Myler's conversion simple for a 12-0 interval lead.
A high tackle from the Dragons on their own 22 saw Myler kick a penalty, and when Pisi intercepted Robson's loose pass to race 60 metres to the line for a try which was converted by Myler, Saints led 22-0 and it looked like a long night for the visitors.
The Welsh side hit back when scrum-half Charlie Davies placed a neat grubber over the Saints' line for Thomas to fall on, converted well by Thomas.
Yet that just wound up the Saints as Reinach grabbed the bonus point try, that Myler converted, and a dash down the left wing by Mallinder was finished by former England flanker Wood.
The spirited Dragons kept their heads up and tried to play enterprising rugby - but their errors were their Achilles heel.
The visitors were not helped in the final minutes when full-back Joe Goodchild deliberately knocked on inside his own 22 and received a yellow card.
And Saints finished with a flourish as Mitchell dived over from a metre, for Grayson to convert.