Bath secured their Guinness Premiership place for next season with an unstoppable first-half performance against Bristol.

Bristol knew before kick-off that Leeds' failure to secure a win at London Irish had made relegation an impossibility but Bath still had to eradicate the mathematical uncertainty.

The derby atmosphere in front of a full house at the Recreation Ground would have been quite enough to sustain the tension in any circumstances however.

Bristol coach Richard Hill kept faith with the side that all but delivered the goods against Newcastle last weekend while Bath kept Olly Barkley at fly-half after Chris Malone had failed to recover from a calf injury and Lee Mears and Zak Feaunati were restored to the pack.

Bath coach Brian Ashton was looking for the kind of performance that would put his side in the right frame of mind before next weekend's Heineken Cup semi-final away to Biarritz.

They responded with an irrepressible display in the first 40 minutes during which Bristol saw hardly any of the ball although Bath's point-scoring took time to build momentum.

Barkley kicked penalties after five and eight minutes and missed another on 10 minutes before Jason Strange landed a 43-metre kick for Bristol five minutes later.

Bristol's rearguard effort was further disrupted when second-row Nathan Budgett was stretchered off after prolonged treatment for a shoulder injury.

Bristol thought they had scored against the run of play after only 19 minutes but Rob Higgitt's pass to David Lemi was called forward.

The breakthrough came for Bath four minutes later when blindside flanker Andy Beattie collected Barkley's inch-perfect cross-field chip to score in the corner. Barkley was unable to convert but added a third penalty, the incident also resulting in a sin-binning for Budgett's replacement Roy Winters as referee Dave Pearson lost patience with Bristol's persistent infringement.

Strange kept Bristol in touch with his second penalty but a searing break by Andy Higgins set up Barkley for a simple kick under the posts.

Bristol found themselves down to 13 men when prop Darren Crompton joined Winters in the sin bin and Bath quickly took advantage as Joe Maddock finished off a spell of heavy pressure at the posts with Barkley adding the conversion.

Winters' return could not halt the onslaught and Feaunati completed a length-of-the-field move - the best try seen at the Rec this season - also converted by Barkley to send the home side in 31-6 at the break.

Bristol came out for the second half looking more purposeful and received the confidence-booster they needed when Bath lost possession behind a scrum and Higgitt kicked down field.

Lemi was quickest to react, hacking ahead to touch down under the posts on 44 minutes. Strange converted and also added his third penalty three minutes later to reduce Bath's lead to 15 points.

After a rush of 24 points in little more than 10 minutes' play, the game became a scrappy contest for possession especially when the substitutes entered the fray, and there was no further scoring.

Bristol came closest with a succession of five-metre scrums and, after Danny Grewcock was yellow-carded on 72 minutes, Bristol lock Mariano Sambucetti was denied a try by the video ref. It was Bath who ended the game on the defensive but the side with the worst home record in the Premiership had achieved the win they needed.