A drop-goal in the last minute of normal time by Chris Malone earned Bath the narrowest of victories in front of a record Zurich Premiership crowd of 22,840 at the Madejski Stadium.

The league leaders, shorn of eight international players behind the scrum, extended their advantage over second-placed Wasps to six points.

Irish thought they had snatched victory in the ninth minute of injury time but Barry Everitt's drop-goal attempt fell just wide of the post.

Bath's success was due entirely to their pack, which fashioned two tries from driving mauls in each half while the Exiles were left with only a modicum of possession for their more dangerous-looking back line.

The unique atmosphere of London Irish's postponed St Patrick's Day party had contributed to a frenetic start.

The roof was raised after nine minutes when right wing Paul Sackey profited from unusually sloppy line-out play by Bath to claim the first try for the home side.

Bath hooker Jonathan Humphreys threw too long, Kieron Dawson drove deep into the Bath 22 and quick transfer of the ball gave Sackey the glimpse of the line he needed.

Mark Mapletoft failed with the conversion and missed another chance on 15 minutes, slicing badly his penalty form just 28 metres.

For all the festive camaraderie in the car park, it was a niggly encounter on the field and Bath's scrum-half Martyn Wood was spotted by a touchjudge and penalised for foul play.

But it was his opposite number, Darren Edwards, who was first to see the yellow card as referee Tony Spreadbury sent him to the sinbin on 23 minutes for kicking an opponent. Malone kicked the goal from 40 metres.

Edwards' absence was exploited again on the half hour when Bath opted to take a lineout from a penalty in the Irish 22. The visiting forwards, finally finding their feet, drove prop Duncan Bell over for the unconverted try.

Mapletoft responded with a penalty from 45 metres to bring the scores level and edged Irish into the lead after Wood was sent to the sinbin on 37 minutes for obstruction.

Malone responded with a 50-metre kick from the touchline on the stroke of half-time as the Irish forwards were blamed for starting a punch-up on the touchline.

The exchange of penalties continued after the break when Mapletoft goaled from 45 metres but the Bath forwards hit back with another driving maul from a line-out. Replacement hooker Lee Mears was awarded the try and Malone added the conversion.

Bath were guilty of sitting on their lead during the final quarter and, inevitably, Irish's replacement fly-half Everitt punished a loose-play infringement with a penalty from in front of the posts.

As clueless as Bath appeared in the backs, the combination of hard-working forwards, such as Rob Fidler and number eight Zak Fea'unati ensured that Bath could work their way up field and keep the ball.

Malone grabbed his chance on 79 minutes to open up a 21-17 lead and although Everitt added another three points from a penalty deep into injury time the clock eventually ran out.