Harlequins served emphatic notice of their Guinness Premiership title credentials by sinking play-off rivals Bath at the Recreation Ground.

The league leaders' 13th Premiership victory this season owed everything to a courageous defensive display.

They absorbed all that Bath could throw at them after grinding out an interval lead through a penalty try when they exerted punishing scrum pressure.

Former Bath fly-half Chris Malone kicked a conversion and three penalties, while England international Danny Care added a drop-goal.

Bath, whose next Premiership game is away to in-form Newcastle, could have few complaints.

Their South African World Cup winner Butch James missed three penalties from four attempts, evoking memories of a similarly-poor performance when Bath were last beaten at home in the league by Gloucester almost seven months ago.

Quins though, who have never been crowned English champions, remain firmly on course for a domestic and European double.

They host Leinster in the Heineken Cup quarter-finals next weekend, while one more Premiership victory should be enough to secure a top-four finish.

Bath went into battle without skipper Michael Lipman, who suffered a neck injury during the midweek victory over Wasps, so James Scaysbrook replaced him in the back-row and centre Alex Crockett took over as captain.

Quins showed seven changes from the side that walloped Worcester on Wednesday night, including a late withdrawal that saw captain Will Skinner absent from duty due to food poisoning.

Neil McMillan took Skinner's number seven shirt, while England number eight Nick Easter - making his first start since the RBS 6 Nations Championship ended last month - led the visitors.

Quins, seeking only their second Premiership win at Bath in 10 years, took an eighth-minute lead when Malone landed a penalty.

And Bath, despite looking to move possession wide, showed early signs of struggling to cope with Quins' considerable physical presence around the breakdown.

The visitors secured turnover ball on three occasions during the opening quarter, and it set the tone for a half they dominated through their forwards.

Props Ceri Jones and Mike Ross had a field day in the scrums, and it came as no surprise when referee Dave Pearson awarded Quins a penalty try.

Bath were under relentless pressure in that critical set-piece department, and when they offended once too often, the official was left with a straightforward decision.

Malone added the extras, hoisting Quins into a deserved 10-0 lead, and although James slotted an injury time penalty, the home side found themselves chasing a game they could ill-afford to lose.

James missed an early second-half chance to further cur the deficit when he rifled a 30-metre penalty wide, before a Malone strike restored Quins' 10-point advantage.

Quins though, then had Ross sin-binned for a technical infringement as Bath generated their most concerted spell of pressure in the contest.

But the Quins front-row refused to buckle, and it was an example that spread to the defensive line as some superb tackling denied Bath and their most dangerous attacker, former Bradford Bulls rugby league star Shontayne Hape.

With Ross reduced to a temporary role of spectator, Bath had opportunities to make their one-man advantage count, yet Quins admirable resilience underlined their position as Premiership top-dogs was no fluke.

Bath increasingly looked to wing Joe Maddock - the Premiership's leading try-scorer this season - for inspiration, but Quins had no intention of letting him hurt them.

And when Care dropped a goal 10 minutes from time, there was no way back for Bath as they ended the game defending grimly.

Quins went for the jugular, and Bath once again infringed, conceding another penalty that Malone landed with just 40 seconds remaining.