Olly Barkley kicked seven penalties out of seven to ensure that Bath maintained their remarkable record of never having lost a league match to their west country neighbours in two decades.
Victory lifted them into eighth place in the Guinness Premiership above Sale while Gloucester spurned the chance to regain top spot over Leicester with two games remaining.
Gloucester scored the only tries, through Will James and James Bailey, and looked at one stage to be cruising to victory but they were ultimately drawn into a derby dogfight as the Bath forwards grew in strength and confidence. Bath made two changes from the side that put 50 points on Bristol in the European Challenge Cup, Andy Williams for Nick Walshe at scrum-half and Lee Mears at hooker for Peter Dickson.
Former Bath favourites Mike Tindall and Iain Balshaw took their places in the Gloucester backline but Alex Brown (shoulder) and Mefin Davies (family illness) were replaced by second row James and hooker Olivier Azam. Gloucester indiscipline in the loose handed the home side a 6-0 lead in as many minutes in bright sunshine, Barkley immediately finding his range from 38 and 40 metres.
But when Chris Malone missed touch Gloucester came back on the attack and Ryan Lamb responded with a successful kick after Matt Stevens was penalised at a ruck. The fly-half missed with another chance on 16 minutes but Barkley was on target again in front of the Gloucester posts after visiting skipper Marco Bortolami was sin-binned for a professional foul on 20 minutes. Four minutes later it was Bath’s number eight Zak Feaunati who was shown the yellow card in similar circumstances but Lamb was wide again with the kick.
Bath’s defence, already hampered by the loss of wing Joe Maddock with a thigh strain, finally cracked when James strode through to the line from a short pass from Peter Buxton on 26 minutes with Lamb adding a conversion. Six minutes later the fly-half cut through on an arching run to lay on a fine try for Bailey on the left wing. Lamb’s conversion attempt rebounded off the post but Gloucester still led 15-9 at half-time.
Lamb and Barkley swapped penalties after the break but Gloucester looked by far the more comfortable side on the ball enjoying good, quick possession at the breakdown against the more laboured kick and drive tactics of the home team. But with Barkley landing his fifth and sixth kicks to another by Lamb, Bath were still only three points adrift on the hour. Both sides were making mistakes but Gloucester in particular were losing the continuity and the rhythm that had made them so dangerous in the first half.
Even when shoved off a scrum on their own line, Bath tackled tigerishly to recover possession and it was eventually a high tackle by James on full-back Nick Abendanon that gave Barkley chance to grab a share of the points on 74 minutes which he took.