Bath Rugby were denied an opportunity to move to the top of the Aviva Premiership after going down to an 3-18 home derby defeat to Gloucester.
The loss was only Bath's second at the hands of their old rivals at the Recreation Ground since leagues began in 1987 - and their first home defeat in the Premiership since London Irish's triumph last November.
A victory of any kind would have sent Bath to the top of the table - but they were under pressure throughout the match and failed to recover following first-half tries from Lesley Vainikolo and Nicky Robinson.
The final result of 3-18 was also the half-time score after Bath went - and then remained - behind following Vainikolo's ninth-minute score. Robinson added the conversion, and then a penalty, before Olly Barkley kicked Bath's only points of the evening on 24 minutes. The visitors added a second try through Robinson, who then compounded Bath's misery with a long-range penalty on the stroke of half-time.
For Bath, who lost captain Luke Watson at the break and Lewis Moody three minutes into the second period to injury, there was no route back on a difficult and frustrating night under floodlights at the Rec.
The second period saw Bath trying to force a way through the Gloucester defensive line - but, as time ran out, the visitors were able to force the home side into mistakes and they closed out victory.
Bath Head Coach, Steve Meehan, said: "Tactically, we made every wrong decision we possibly could have in that first 20 minutes and Gloucester grew. They made all the right ones and made all the running, grew in confidence and exposed us at every opportunity they could.
"By the time half-time came, a lot of damage had been done - and, while our enthusiasm was raised in the second half, we just couldn't control the ball long enough to convert any of our field position into points."
Bath had hoped to build on last weekend's home victory over Sale Sharks, but were never really able to establish any rhythm against a dogged Gloucester side, who followed up their recent win against Wasps.
The hosts were relieved when Robinson failed with a long-range penalty attempt during the opening exchanges but they soon fell 0-7 down when Gloucester capitalised on the first of many Bath knock-ons.
Nick Abendanon gathered a high ball, but as Bath moved the ball away from the ruck, they coughed up possession and Gloucester attacked them at pace. Eliota Fuimaono-Sapolu and Robinson combined quickly to send Vainikolo to the line - and Robinson knocked over the conversion for 0-7.
Robinson then rattled the right-hand upright with a penalty attempt, before making it 0-10 shortly after following a ruck infringement.
Barkley, playing against his former club, responded with a penalty, after Oliver Azam was caught entering a ruck from the side, but any hopes of a Bath fightback were short-lived as Gloucester pounced for a second try virtually straight from the restart.
Mike Tindall broke through the midfield with purpose, Robinson kicked down-field and Fuimaono-Sapolu gave chase, gathering the ball before setting up Vainikolo, who quickly passed to the supporting Robinson to score.
The Welshman missed from the touchline, before Barkley saw a long-range penalty attempt fall just short. Robinson then missed again from distance, before extending his side's lead to 15 points on the stroke of half-time with a 45-metre penalty.
Skipper Watson went off with at the break - and three minutes later Moody joined him after colliding with Charlie Sharples as he tried to charge the full-back's clearance.
Gloucester lost a key forward of their own when lock Jim Hamilton was shown a yellow card for flicking a foot out and kicking the ball away while lying at a ruck, but Bath could not exploit their numerical advantage.
After Gloucester were restored to their full complement, Bath enjoyed several periods of sustained pressure in the visitors' 22 but despite kicking penalties to touch and taking close-range scrums they were generally let down by the most basic of handling errors at crucial times.
Gloucester held firm in defence, despite Bath's increased energy levels around the park, with the visitors' composure the key component in their victory.
Tonight's Match Day sponsor was Pullen Brickwork Ltd, and the Match Ball Sponsor was Total Star Radio Bath.