A virtuoso first-half performance from Nicky Robinson guided Gloucester to only their second Aviva Premiership Rugby win at Bath and denied the home team a record ninth successive home victory.
At a rain-soaked Recreation Ground the former Wales fly-half tormented Bath with his tactical kicking and scored a crucial 25th-minute try. He also kicked a conversion and two penalties. Bath's high-tempo game was undermined by spilled possession and their only answer was an Olly Barkley penalty. Neither team scored in the second half.
Robinson was only recalled to the Cherry and Whites' team after Tim Taylor was ruled out with a leg injury. Barely a minute had elapsed when Gloucester lock Jim Hamilton and Stuart Hooper squared up to each other, proving that the visitors were in no mood to roll over, despite their inconsistent form this season.
Gloucester took the lead after nine minutes when Robinson hoisted a high kick which both Nick Abendanon and Matt Carraro failed to secure. Paul Doran-Jones picked up the loose ball and fed Eliota Fuimaono-Sapolu who put Lesley Vainikolo over in the corner. Robinson converted from the touchline.
Bath were inviting trouble by trying to play high-tempo rugby on the slippery surface, spilling passes and conceding penalties. Skipper Luke Watson clumsily clattered into Charlie Sharples chasing a kick, Robinson's penalty shaving the post, and then the number eight made a fine break only to spill the ball forward.
Robinson did find the target to make it 10-0 after 21 minutes and, although Barkley replied with a difficult angled kick, Robinson immediately hit back with a 25th-minute try. It was his perfectly-judged kick through that had the Bath defence in disarray.
Fuimaono-Sapolu was first to the ball, flicked it up to Vainikolo who found his fly-half with a pass out of the tackle. Robinson could not convert his own try but added another penalty just before the break to send his team in 18-3 ahead.
Freddie Burns replaced Robinson at the break, clearly not a tactical change, and Gloucester were further disrupted when Hamilton was yellow carded on 42 minutes for needlessly kicking out at the ball on the wrong side of a ruck. At the same time however, England captain Lewis Moody had to go off after a sickening collision with Sharples, replaced by Josh Ovens.
Bath continued their helter-skelter approach but it was Gloucester's calmer rugby which proved the more effective. Bath's line-out and scrum also came under severe pressure at vital moments, denying them the platform they needed to take the game to Gloucester.
Even when they did find their way into the visitors' 22, their handling let them down again and, although three penalties were given against Gloucester in five minutes, the fourth time Wayne Barnes blew his whistle it was for a Bath scrummage offence and Gloucester cleared their lines.