Paul Grayson kicked Northampton to a 29-11 victory over Bath to add to the west country side's fears of relegation out of the top flight.

Bath desperately needed victory to try to climb away from the Premiership danger zone but successive defeats against Saracens, Leicester and Sale did not auger well against a Northampton side high on confidence.

The Saints, who went into action with England wing Ben Cohen among their replacements, knew that only a second league win on Bath soil would take them fifth, underlining a considerable improvement since former All Blacks coach Wayne Smith arrived from New Zealand before Christmas.

Bath boss Michael Foley made three changes from the team thumped by Saracens two weeks ago, calling up wing Rob Thirlby, hooker Andy Long and flanker James Scaysbrook - all on form - instead of Tom Voyce, Mark Regan and Nathan Thomas, respectively.

Home fly-half Olly Barkley missed a first-minute penalty chance when he rifled the ball wide from 35 metres, and then drifted a drop-goal attempt across the posts as Bath's forwards established early territorial supremacy.

Barkley continued to struggle, missing another penalty opportunity on 12 minutes, but he then found his range, putting Bath 3-0 ahead with Northampton guilty of repeated infringing.

Saints quickly drew level though, fly-half Grayson landing a penalty, yet he missed a similar chance after Bath prop John Mallett was warned following an off-the-ball incident involving Northampton number eight Grant Seely.

Grayson edged Northampton ahead through his second penalty on 26 minutes, yet the overall playing standard was desperately poor in perfect conditions.

Neither team possessed the creative flair or instinct to create anything worthwhile in attack, and referee Chris White's half-time whistle came as a merciful release from such dreadful mediocrity.

Cohen appeared for the second half, replacing last season's England Under-21 captain Mark Tucker, and Northampton immediately extended their advantage when Grayson completed his penalty hat-trick.

England international Iain Balshaw put Bath on the front foot through a raking touch-finder, but home centre Alex Crockett knocked possession forward after Grayson and Saints midfield man John Leslie messed up in defence.

Grayson's fourth penalty made it 12-3 to Northampton after 56 minutes, and Foley began ringing the changes as Bath saw their victory hopes fade.

Simon Emms replaced Mallett, while Nathan Thomas went on for Scaysbrook and Voyce took over from Barkley, which meant Balshaw moving to fly-half and wing Rob Thirlby filling the full-back role.

Northampton though, having replaced England hooker Steve Thompson with Dan Richmond, then scored the game's opening try.

Flanker Andrew Blowers charged down centre Mike Tindall's kick, scrum-half Matt Dawson took the move on, and wing James Brooks touched down wide out.

Although Tindall, Bath's goalkicker in the absence of Barkley, kicked a 62nd-minute penalty, Bath still had it all to do, trailing 17-6.

Bath threw everything at Northampton in an attempt to rescue the game, and their determination was rewarded 14 minutes from time.

Sustained pressure inside the Saints' 22, saw Northampton eventually run out of defensive numbers, and substitute Voyce grabbed a try that gave Bath a lifeline, even though Tindall could not convert and further dent the visitors' 17-11 advantage.

Northampton were suddenly under the cosh, but they reacted superbly and continued the scoring flurry on 71 minutes.

The Saints forwards ran aggressively at a tiring Bath defence, and substitute hooker Dan Richmond blasted through for Northampton's second try.

Grayson added the conversion for a 24-11 lead, seemingly destroying Bath's hopes of collecting a bonus point.

Tom Smith's high tackle on Balshaw prompted Bath's England and Lions lock Danny Grewcock to throw a haymaker at Smith, and fortunately for both parties, it did not connect.

In injury time, Northampton claimed their third try when centre Peter Jorgensen showed the defence a clean pair of heels to cross wide out.

It was the Australian's fourth touchdown in three games. Bath were now down and out, relegation remaining a stark reality as Northampton triumphed 29-11.