Bourgoin (0) 7
Allen's fine solo effort set Gloucester on their way to victory
Gloucester (17) 31
Tries: Allen, Simpson-Daniel, Lamb, Titterrell
Cons: Lamb 4
Gloucester took a firm grip on Heineken Cup Pool Two with a bonus-point victory away to Bourgoin in eastern France.
Gloucester dominated the first hour and led 17-0 at half-time thanks to Anthony Allen and James Simpson-Daniel tries.
Ryan Lamb grabbed their third score and although Julien Frier crossed for the hosts, Andy Titterrell grabbed the crucial fourth try in injury-time.
Gloucester's joy was tempered by injuries to Olly Morgan, Mike Tindall and Chris Paterson.
The English league leaders took a fifth minute lead when Allen cut through the home defence to score a solo effort.
Lamb, glad to put his arrest and night in the cells last weekend behind him, converted and the fly-half added a penalty just after the 20-minute mark as the visitors stamped their authority on the game from the start.
Despite a number of successes on Gloucester's line-out the Cherry and Whites' power up front and pace out wide meant the hosts remained under the cosh up to half-time.
And they conceded a second try when Lamb's delightful side-step and delayed pass from an attacking line-out enabled Simpson-Daniel to dance over, with Lamb adding the extras.
The winger could have made it even better for Gloucester but, when Lamb chipped through after a sweeping counter-attack, Simpson-Daniel knocked on as he tried to pick up at pace and dive over.
Gloucester led 17-0 at the break and although they came close to conceding a try when Bourgoin open-side Mark Rennie nearly raced over on the counter-attack, Lamb quickly settled their nerves.
The impish number 10 intercepted an over-ambitious pass in midfield and cruised over under the posts to make his conversion a formality.
Gloucester then lost Morgan and Tindall to injury and the hosts finally began to get into the game as the wind picked up and the rain began to hammer down.
Iain Balshaw, who was later temporarily forced off with a cut shin, produced a superb corner-flag tackle to keep flying winger David Janin at bay but two minutes later Frier crashed over from short range.
Benjamin Boyet's conversion made it 24-7 and Gloucester's injury situation went from bad to worse as the visitors, who briefly had 16 players on the field, lost replacement Paterson to injury.
Bourgoin enjoyed the better of the closing stages but Gloucester managed to raise the siege and grabbed a bonus point when Titterrell plunged over for a fourth converted try in the last move of the game.
Gloucester boss Dean Ryan:
"Olly's [Morgan] shoulder is pretty serious, Chris's [Paterson] ribs looked pretty sore and Tins [Mike Tindall] took a bad bang on his shin - in that order. We'll see tomorrow.
"Without a doubt, today and next week is going to test our resources. There were some significant injuries out there.
"It's an enormous win. It's the toughest game we had in the pool.
"They were a fired up Bourgoin and I thought our first 20 minutes and then our first 10 minutes after half-time were outstanding and that gave us full control of the game."
Bourgoin: A Forest; Janin, Coetzee, Laloo, M Nicolas; Boyet, Parra; Wihongi, Cabello, Cardinali, Pierre, Fevre, Frier, Rennie, Jooste.
Replacements: Genevois, Sourgens, Wyatt, S Nicolas, M Forest, Viazzo, Coux.
Gloucester: Morgan; Simpson-Daniel, Tindall, Allen, Balshaw; Lamb, Lawson; Wood, Azam, Nieto, Buxton, Brown, Strokosch, Qera, Delve.
Replacements: Titterrell, Califano, W. James, Narraway, Cooper, Paterson, Lloyd.
Referee: Alain Rolland (Ireland)