What had been a passionate and hard fought encounter, completely disintegrated in the final few minutes with Gloucester clinging on to a 17-11 lead.
They were doing so with only fourteen men, Sila Puafisi having been shown a straight red for a high tackle. But his team mates had hung in there, dug deep and deservedly taken the lead.
But the final few minutes almost defy description. Firstly Mike Tindall was yellow carded for killing the ball. He was swiftly followed by Huia Edmonds for taking out the jumper at the lineout.
When Bath finally took advantage of only playing against 12 men and were awarded a penalty try, frustration finally spilled over - on and off the pitch. Tavis Knoyle was red carded and Kingsholm erupted in boos.
George Ford kicked the conversion to snatch the win for the visitors, and everyone was left to ponder on what on earth had just happened.
The biggest frustration was that Gloucester had probably just about deserved the win. They'd played with real determination and no little ambition. The accuracy was lacking at times, but you couldn't fault the effort.
When the fourteen men dragged themselves back in front, there was a genuine feeling that Gloucester were going to clinch a richly merited four points - until the madness of the final few minutes.
The challenge now is to bounce back ahead of next Saturday's trip to Twickenham to take on Wasps. That game now takes on huge importance with Wasps having lost at Leicester today.
Gloucester started in confident fashion, moving the ball left and right, probing for an opening. But the Bath defence was committed and robust in the early exchanges.
However, there was some reward for Gloucester's dominance of possession as Billy Twelvetrees slotted a fifth minute penalty when a Bath tackler failed to roll away.
There was plenty of ambition from the Cherry and Whites, and a length of the field attack deserved better. However, Bath served notice of their power up front with a dangerous catch and drive which Gloucester did well to survive.
But Bath did level the scores after 13 minutes, when Gloucester were penalised at a 5 metre scrum. George Ford will have struck kicks better in his career, but the penalty went through the uprights.
Gloucester had a good scoring opportunity from a 5 metre lineout, but were penalised for a man in front of the ball carrier, while Bath had an Agulla try chalked off for blocking. It was frenetic stuff.
As the game went into its second quarter, Bath, with the wind at their backs, were enjoying the better of the territorial battle, but there was little to choose between the sides.
But Gloucester nudged their way back in front on 25 minutes, with a second Twelvetrees penalty when Bath were pinged again at the tackle area.
And the advantage was doubled a few minutes later, when Carl Fearns blatantly played the ball on the ground in front of his own posts, was duly yellow carded and Twelvetrees had an easy third penalty.
It was feisty stuff, and both teams received a lecture as a scrum disintegrated into argy-bargy. Bath struck the next blow on the scoreboard though, with a 36th minute penalty from Ford.
Twelvetrees struck the upright with a penalty attempt as Bath were, yet again, penalised at the breakdown area, and the half finished in dramatic fashion with Matt Garvey sinbinned for a high tackle on Gareth Evans.
It had been a pulsating arm wrestle of a first half of rugby. It was as passionate as you'd expect a Gloucester-Bath derby to be, with neither side taking a backward step.
Gloucester could perhaps derive some satisfaction from having played into the wind in the first half, but Bath had shown glimpses of what they were capable of with ball in hand.
A big second half lie ahead of the sell out Kingsholm crowd. Bath would start with only 14 men on the pitch again - could Gloucester take advantage?
There was certainly mixed news for Gloucester at half time. Mike Tindall returned after a concussion assessment, but Gareth Evans failed to recover from Garvey's tackle and was replaced by Ben Morgan.
Despite being a man light, Bath started well, wisely keeping hold of the ball wherever possible. Ford was well short with a penalty attempt into the wind and also hit the upright with a drop goal.
Gloucester were struggling to get out of their own half as Bath kept the pressure on and, when Garvey returned from the sin bin, the score remained the same.
The momentum then swung the way of the visitors when Sila Puafisi was red carded for a high tackle on Nick Abendanon. It was a pivotal moment in the game.
Bath promptly took full advantage. With a superiority in numbers up front, they kicked a penalty to the corner and skipper Stuart Hooper touched down to give his side a 9-11 lead.
It was now backs to the wall time for the Cherry and Whites. It was only a two point margin, but Bath had the ascendancy as the game went into its final quarter.
Twelvetrees was off target with a penalty from well inside his own half, and the tension grew despite the home crowd doing everything to lift their side. But it was a change of personnel that did the trick.
Nigel Davies threw Tavis Knoyle and Rob Cook into the fray, and the latter's superb break from deep led to a yellow card for Dave Attwood. Twelvetrees' penalty was well struck and took Gloucester into the lead.
There was renewed belief in Nigel Davies' side, and they then scored what looked to be a crucial try.
Matt Kvesic, superb all afternoon, drove Bath off their own ball at a ruck. Tavis Knoyle shipped the ball out to Mike Tindall, who delayed his pass nicely for Henry Trinder to dummy his way clear and over for the try.
Crucially, Billy Twelvetrees couldn't convert and it was only a six point lead going into the final few minutes.
Bath threw the kitchen sink at Gloucester, but the gallant 14 men were holding firm, with the incredible support of the home crowd behind them.
Charlie Sharples nearly picked off an errant pass but couldn't hold on when he would surely have gone all the way. Freddie Burns had a great chance to clear and ease the pressure but was charged down.
But it wasn't to be, and the debate will go on long into the evening….
|Gloucester Rugby Score Card|
|Bath Rugby Score Card|