Gloucester staged a stunning fightback to shrug off their Heineken Cup hangover and climb to the top of the Guinness Premiership after defeating previous leaders London Irish at Kingsholm.

Wing Iain Balshaw crossed the whitewash for the match-winning score in the first minute of second-half stoppage time.

But the win has come at a cost after 19-year-old scrum-half Dave Lewis was carried off on a stretcher with a suspected broken ankle.

With Gareth Cooper and Rory Lawson in the Wales and Scotland squads respectively for the forthcoming Six Nations Championship, the Cherry and Whites have a No 9 crisis on their hands.

Gloucester were 10-0 down after 13 minutes, Exiles fly-half Peter Hewat kicking a penalty and converting a try from Adam Thompstone.

The winger skipped through some very weak tackles by the Cherry and Whites to go over from five metres out after Gloucester scrum-half Rory Lawson had fumbled a Paul Hodgson kick.

But it got worse for the hosts on 22 minutes when the Exiles scored their second try.

No 8 Chris Hala'Ufia made the initial inroad after a Thompstone offload. The ball was recycled and spun to the right wing where full-back Delon Armitage passed out of the tackle for Topsy Ojo to dive over.

Gloucester were finally on the scoreboard on 31 minutes when Olly Barkley landed a straightforward penalty after Irish were guilty of not rolling away at a ruck.

Hewat extended the Exiles' lead with a penalty on 39 minutes but that was cancelled out two minutes later by Barkley's second goal of the afternoon.

The hosts finished the half well but had to settle for a third Barkley penalty after Irish were offside.

Gloucester's injury jinx struck again on 50 minutes when replacement scrum-half Lewis had to be carried off on a stretcher with a suspected broken left ankle after being hurt in a tackle by Hala'Ufia.

Ryan Lamb, normally a scrum-half, was forced to play out of position and could make a permanent switch there with Premiership matches against Sale and Bath clashing with Six Nations games.

But the hosts were reduced to 14 men on 58 minutes when centre Anthony Allen committed a professional foul when he didn't roll away after a tackle.

Hewat kicked the resulting penalty to take the Exiles 21-9 ahead but Barkley reduced the deficit with a 64th-minute penalty.

London Irish's lead was only five points three minutes later when Barkley was again on target after Hala'Ufia's high tackle on Olivier Azam.

The Exiles' poor discipline continued with centre Seilala Mapusua being shown a yellow card for not rolling away on 70 minutes.

Barkley hit the resulting penalty before Gloucester were ahead for the first time in the first minute of second-half injury time.

A cut out pass to Allen handed the Cherry and Whites' three-quarters space for full-back Willie Walker to send Balshaw over.

Barkley could have added to Gloucester's total seconds before the final whistle but his 35-metre penalty drifted wide of the left-hand upright.