Recalled England fly-half Paul Grayson contributed 17 points as the Saints compounded Bath's relegation woes ahead of the 2003/04 season, the home team remaining in last place on the Zurich Premiership standings.
Grayson, who won an England reprieve after a serious knee injury to Charlie Hodgson, kicked two conversions and five penalties as his side ran away with things in the second half over the Premiership strugglers.
Northampton, who started the match with England players, prop Robbie Morris and scrum-half Matt Dawson, held a 16-3 half-time lead, and went on to score a further 11 unanswered points before Bath finally scored a try in the 80th minute through left-wing Tom Voyce, a late starter after Kevin Maggs and Matt Perry withdrew before kick-off.
But that was to be the home team's only try, the visitors outscoring their hosts by two tries to one, former Australian midfielder Peter Jorgensen scoring both of the tries.
Jorgensen scored one of his tries in the first half, the other in the second, the first coming from a clever Grayson kick-ahead.
Both teams had players spend some time in the sin bin shortly before half-time, Bath's lock and captain Danny Grewcock being involved in a skirmish with his opposite number, former Wallaby utility forward Mark Connors.
For Bath:Try: VoyceCon: BarkleyPen: Barkley
For Northampton:Tries: Jorgensen 2Con: GraysonPens: Grayson 5