Bath moved into the Zurich Premiership title picture - and compounded Northampton's relegation fears - after claiming a comfortable home victory.

The West Country club, Powergen Cup finalists against Leeds at Twickenham next Saturday, swamped lowly Saints to wrestle third place from Sale Sharks.

And it means that Bath will effectively be guaranteed a May 6 semi-final clash away to Wasps or Leicester if they triumph in their remaining two league appointments with struggling London Irish and Leeds later this month.

They reached the Premiership final last season, being pipped for championship glory by Wasps, and a return visit cannot be ruled out, given their enviable forward power.

Bath coach John Connolly will be disappointed that his team couldn't convert their first-half dominance into a try-scoring bonus point, yet they at least have control over their play-off destiny.

Northampton, meanwhile, are still trapped in the danger zone, fighting for top-flight survival.

But on this evidence their league position is not a false one as Bath brushed them aside, making the game safe by establishing a 23-6 interval advantage through tries from full-back Joe Maddock and centre Andrew Higgins, while prop Duncan Bell added a third touchdown late on.

Chris Malone kept the scoreboard ticking over as he slotted two penalties, three conversions and a drop-goal, and it proved pretty much a routine afternoon's work for Bath as Northampton could offer little serious threat.

Saints, without key injured forwards Tom Smith, Andrew Blowers and Corne Krige, lacked the forward cohesion to trouble a Bath pack that has dominated most Premiership opponents this season.

They were also devoid of inspiration on occasions, as star backs Bruce Reihana and Ben Cohen found themselves too far away from the action to make any telling contributions.

Fly-half Shane Drahm kicked three penalties and a drop-goal for Saints, but it said everything about Northampton's limitations that he always looked their most likely source of points.

Northampton dominated early possession, and they shaded the opening quarter 6-3 thanks to Drahm's accuracy, but any Saints momentum was badly disrupted when England hooker Steve Thompson and Scotland flanker Ross Beattie both required treatment for cuts in quick succession.

Thompson, a clear favourite to be the Lions Test hooker in New Zealand this summer, was off for almost 10 minutes receiving treatment to a cut above his left eye, and Bath turned the screw.

Slick passing from Malone and the impressive Olly Barkley sent Maddock over for a 30th-minute touchdown, then concerted forward pressure sucked in Saints defenders and Higgins sprinted through a huge gap created by Barkley's superbly-timed pass.

Malone booted both conversions and kicked a penalty during first-half injury time, leaving Northampton with a mountain to climb.

The second period began in similar fashion to the first - Northampton enjoying an abundance of possession, but doing precious little with it - and Bath gradually gained territorial dominance.

Drahm's penalty double in the 61st and 63rd minutes lifted Saints for the closing stages, as Bath became strangely subdued, almost as if they had a collective eye on next week's Twickenham trip.

Skipper Steve Borthwick tried to encourage his players for a rousing finale, and Bath finished strongly - predictably through their forwards - laying siege on Northampton's line.

Saints' former Bath prop Simon Emms was sin-binned for a technical offence, compounding the degree of difficulty for Northampton, and Bath punished them before he could even leave the field.

With Emms still trudging off, the Bath pack drove relentlessly towards Northampton's posts, and Bell claimed his team's third try, improved by Malone to give the home fly-half 15 points.