After a poor recent run of form that included a humbling 48-17 defeat at the hands of the Leicester Tigers, the Wasps refound their appetite for the contest, and managed to put eight tries past the startled Saints.
Indeed, the pure power of the home side's performance would have been noted – grimly – by Toulouse, who the Londoners face in the Heineken Cup final next Sunday.
Northampton, who were also beaten by Wasps in the corresponding fixture last year, started well and led 6-0 through two Bruce Reihana penalties after only 10 minutes.
Wasps were slow to shake off the disappointments of the last couple of weeks, and made a meek start to the game, with Alex King slotted a penalty and missing another.
The visitors kept up the pressure on the slumbering giants, and Paul Grayson attempted to extend the Saints' lead with an impromptu drop-goal, but his effort sailed wide.
It was left to Voyce to get his side moving, and he did so with a superb solo try on the half-hour mark.
The wing received the ball on the halfway line and stepped past two defenders before shrugging Ben Cohen off his back to dot down in the corner.
Wasps substituted grace for grunt for their second try, scored in the 37th minute of the game. England captain Lawrence Dallaglio rumbled round the front of a lineout and was driven over the line by the industrious Simon Shaw.
Wasps then managed to squeeze in a third try at the stroke of half time, when Shaw drew two defenders before releasing Ayoola Erinle – on for Fraser Waters – who beat Bruce Reihana's challenge to race home for the score.
Emerging from the break at 22-6 to the bad, Northampton attempted to make inroads into Wasps' lead – but Mark Robinson may have been guilty of trying to hard after his pass was intercepted by Stuart Abbott who raced home to score from his own 22.
With the game all but won, Wasps boss Warren Gatland substituted the likes of Rob Howley, Abbott, Shaw and Trevor Leota as minds began to ponder European glory.
Northampton reacted to the snub by sending Andrew Blowers in for a well-taken try, but Wasps responded with triple interest.
Paul Volley twisting over after receiving a cross-field kick from Josh Lewsey, Voyce then cantered over for his second try, before prop Tim Payne was driven over for another.
Nick Beal, in his last game for the Saints, grabbed a late try, but he was denied the last word by his erstwhile England colleague, Dallaglio, who thumped his way over for a late try.
Wasps will now meet Bath in the Zurich Premiership Final at Twickenham on May 29, a game that will reveal the identity of the 2003/04 Zurich Premiership Champions.
For London Wasps:Tries: Voyce 2, Dallaglio 2, Erinle, Abbott, Volley, Payne Cons: van Gisbergen 7Pen: King
For Northampton Saints:Tries: Blowers, BealCons: Reihana 2Pens: Reihana 2