Wasps' miserable run of form continued as they crashed to another defeat after being beaten 36-17 by Northampton at Franklin's Gardens.
It was their seventh match without a win in all competitions – six defeats and a draw – and they looked a side short on confidence in the absence of many of their leading players.
Northampton did not need to be at their best to secure the win but still scored five tries through Andrew Kellaway, Ollie Sleightholme, Fraser Dingwall, Taqele Naiyaravoro and Piers Francis. James Grayson succeeded with two penalties with Francis kicking another penalty and a conversion.
Thomas Young and Josh Bassett scored Wasps' tries with Lima Sopoaga kicking a penalty and conversion. Billy Searle also added a conversion.
Wasps conceded a couple of early penalties for not releasing, which gave the hosts a platform in the opposition 22 from where they scored a sixth minute try.
Kellaway burst past two defenders to put the visitors' defence on the back foot before a well-judged cross-field kick from Grayson was collected by Kellaway to score.
Grayson made a hash of the conversion attempt but kicked a simple penalty to give his side an 8-0 lead at the end of an uneventful first quarter.
During that period, Wasps had more possession but inaccurate passing and frequent turnovers prevented them from getting onto the scoreboard.
In terms of errors, the home side were not much better but in Fijian wing Naiyaravoro, they possessed the game's major attacking weapon as he produced a number of powerful runs.
Wasps had their first chance for points but Sopoaga's 45-metre penalty attempt was nowhere near before their flanker Thomas Young was sin-binned for collapsing a driving maul.
Grayson kicked another simple penalty before straight from the restart, Saints scored their second try when Naiyaravoro burst past a couple of defenders to run 40 metres and give Dingwall an easy run-in.
Grayson's conversion attempt was again poor before Sopoaga kicked a penalty to leave Wasps trailing 16-3 at the interval.
Northampton prop Ben Franks was replaced for the second half by Karl Garside, who came on for his Premiership debut before Saints extended their lead with a try from Francis.
Young returned from the sin-bin at the same time as Wasps wing Marcus Watson departed with a leg injury, as the visitors' woes went from bad to worse.
Watson's replacement, Michael Le Bourgeois, raised their spirits with a neat break before Young crashed over from a driving line-out.
However Naiyaravoro continued to cause havoc and it was he who deservedly picked up the bonus point try after he had easily rounded Rob Miller.
Francis took over the kicking to miss the conversion but his late penalty and an excellent try from Premiership debutant, Sleightholme, emphasised Saints' superiority with Bassett's late try a mere consolation for dispirited Wasps.