Bristol's battle against the drop is gathering momentum despite this latest defeat courtesy of an interception try from former Colston’s School pupil Shane Geraghty with 13 minutes remaining.

They had to settle for a losing bonus point despite completely dominating the second period in front of a disappointing crowd of 6,225.

Richard Hill’s side now take on Northampton in back-to-back European Challenge Cup clashes before returning to Guinness Premiership action for crucial matches over the Christmas period.

They visit Worcester r on December 20, host Gloucester at the Memorial Stadium seven days later and then travel to Northampton on January 3.

Bristol could drag Worcester and Northampton into the relegation dogfight – the Warriors and Saints are only seven and four points clear respectively – but they felt the defeat against the Premiership leaders was a missed opportunity.

Wing Lee Robinson said: “We are all gutted. We had all the pressure in the second half and we lost it so cheaply in the end. It was quite demoralising.

“The dressing room was pretty sombre. The heads were down but we realise that we had a lot of pressure and possession in the second half.

“London Irish are a top-of-the-table side – so there are a few positives to take away.

“The Christmas games are massive for us. We still have to sneak the wins when we can because it will come down to a few close games.”

Hill handed first league starts of the season to Robinson, scrum-half Shaun Perry and centre Luke Eves.

But apart from a barnstorming run by Robinson and good probing by Perry, the hosts had very few chances to score in the first 40 minutes.

They failed to progress to the Irish 22 throughout the first period. Bristol would have enjoyed better territory had their kicking from hand not been so loose and poorly directed.

One such loose kick led to Irish scoring their first try of the afternoon on 32 minutes.

The Exiles were already 6-0 ahead thanks to full-back Peter Hewat’s two penalties when the ball was spread along the line just inside their half for wing Sailosi Tagicakibau to evade weak tackles from Robinson and Perry to touch down.

Bristol were lucky not to concede three other tries during the first 40 minutes. Hooker David Paice was denied a try because of a forward pass before Geraghty and wing Topsy Ojo knocked on when in promising positions.

But Bristol were a different team in the second half – and quickly claimed possession in the Exiles’ 22.

Fly-half Ed Barnes, who started in the No 10 shirt in place of the dropped summer signing Adrian Jarvis, kicked a penalty on 43 minutes.

His delightful crossfield kick set up Bristol’s only try of the afternoon on 54 minutes.

Robinson tapped the ball down to full-back Luke Arscott, who offloaded for Eves to ride a tackle and score. Barnes converted. The No 10 missed a penalty and was off-target with two drop goal attempts, but he kicked Bristol ahead for the first time in the match on 63 minutes with a penalty.

Bristol deserved their lead. Irish just could not get out of their own half and made mistake after mistake.

But the afternoon was to get worse for Barnes – just four minutes after taking Bristol ahead he gave the pass which Geraghty intercepted. The Exiles’ fly-half raced home despite No 8 Dan Ward-Smith chasing hard, with Hewat adding the extras.

Bristol, with second row Robert Sidoli leading the charges, had plenty of time to wrestle back the lead. But they could not break down the Irish defence and their best chance – a kick across to Robinson in space – came to nothing when the ball went into touch.

Head coach Hill said: “It was a bit cruel, but to lose when playing well against a team that is now top bodes well for the future.

“We were played off the park by Gloucester. We didn’t have a chance of winning.

“We played a good Irish side and should have won the game. The players are angry about it but this will bring us closer together.

“We are getting better. The longer we can have to get things right the better. We will change the team around a bit next week (for Northampton away in the European Challenge Cup) but we will get there.”