Bristol ended Gloucester's unbeaten Guinness Premiership record amid dramatic scenes at a packed Memorial Stadium when substitute Jason Strange booted a drop-goal 10 minutes into injury time.

Strange, on for an injured David Hill, slotted his winning kick in the game's final play, taking Bristol back to the Premiership summit.

Their eighth win from nine league starts took them three points clear of Gloucester, who looked to have done enough when fly-half Willie Walker edged them 12-11 ahead just seven minutes earlier.

Walker's 83rd-minute penalty - his fourth successful kick - looked to have deflated Bristol, but their forwards dredged up one last effort to establish a threatening position, and Strange did the rest.

Bristol's former England hooker Mark Regan scored the only try of a scrappy, nervous encounter in front of a capacity 12,000 crowd.

Hill landed a penalty and drop-goal, but Strange grabbed the headlines, sending Gloucester packing through a nerveless strike that immediately saw him engulfed by his ecstatic team-mates as referee Rob Debney's final whistle sounded.

Bristol, unbeaten at home since April, made a dream start as they punished Gloucester from their first attack.

Scrum-half Brian O'Riordan, on starting duty instead of England's Shaun Perry, kicked into space behind the Gloucester defence, and before the visitors could react Bristol number eight Dan Ward-Smith snaffled possession to keep momentum.

Ward-Smith, who has trained with England during the autumn Test series, then recycled possession and Hill switched attacking direction to send Regan over in the corner.

Hill drifted the conversion narrowly wide, but then landed a 45-metre penalty in increasingly blustery conditions as the Gloucester forwards experienced some torrid moments when Bristol's front five moved through the gears.

Walker's opening penalty narrowed the deficit, yet Bristol still looked the more dangerous team in attack and a short-range Hill drop-goal restored an eight-point advantage.

Bristol, though, briefly lost their way as half time approached, with Walker landing two further penalties either side of home centre Rob Higgitt being sin-binned by referee Debney for a technical offence.

Bristol, bemused by a 9-4 penalty count in Gloucester's favour, then had further cause for concern when veteran prop Dave Hilton limped off to be replaced by Alex Clarke, and a two-point interval lead was scant reward, given their territorial dominance.

Driving rain made handling treacherous, although it did not bother the outstanding players on each side - Ward-Smith and England centre Anthony Allen - who looked a class above anyone else in thought and deed.

Ward-Smith continues to make such an impact in only his second season of Premiership rugby that it is a mystery of Agatha Christie proportions why under-fire England head coach Andy Robinson cannot allocate him a place in the Test 22.

Dynamism, pace and power are hallmarks of his game, even in the often claustrophobic environment of an attritional Premiership competition, and Robinson - provided he still has a job after Christmas - must look to Ward-Smith for this season's RBS 6 Nations Championship campaign.

A poor third quarter proved notable only for an escalating error count, and the game lost all momentum as injuries and substitutions contributed heavily to its stop-start nature.

Gloucester, though, exerted pressure when Bristol wing Lee Robinson kicked the ball over his own dead-ball line, conceding a scrum-five despite having time to gather possession and clear it.

But Robinson was not punished for his blunder as Gloucester botched their promising attacking position and were forced to retreat at a rate of knots before centre Mike Tindall's immaculate defensive work kept Bristol out.

Then came the late drama, with Walker edging Gloucester ahead before Strange hit the jackpot and Bristol began prolonged celebrations.