For the second time in a month, Worcester were a thorn in the side of Gloucester's Guinness Premiership ambitions denying the Cherry and Whites with a dogged defensive display.
Dean Ryan's men dominated territory and possession but simply couldn't find the cutting edge required to break down the Worcester defence.
An Olly Barkley penalty in each half was all that Gloucester could muster and a breakaway try from Worcester number eight Nateni Talei proved to be the difference between the two sides.
Desperate to overcome the half time deficit, Gloucester threw themselves body and soul into the task in hand. As time ticked on, the tension grew as did the frustration of the Kingsholm crowd. But each tackle made seemed to inspire Worcester yet further with each player determined not to let him team mates down.
There was no little effort from Gloucester but the sheer effort of having to play a second game in just four days clearly took its toll on the players.
Credit to Worcester. They weathered an early storm, enjoyed the better of the second quarter and took a deserved lead.
Then they simply absorbed everything that Gloucester could throw at them in the second half to leave with the points.
The result leaves Gloucester in fifth place in the Guinness Premiership table with just one round of matches left and four points behind Harlequins, Bath and London Irish.
The match action started well. Gloucester showed their ambition from the off with Carlos Spencer turning down opportunities to kick at goal as Worcester transgressed in and around their own 22.
The home team were enjoying plenty of possession and territory but the Worcester rush defence was up fast and making all their first up tackles.
Olly Barkley slotted a penalty to nudge Gloucester into a 3-0 lead after 11 minutes and it seemed only a matter of time until tries followed with Akapusi Qera particularly prominent in his role as human battering ram.
However, Worcester hung on and held out and slowly but worked their way back into the game thanks to a series of decisions from referee Rob Debney which had the Kingsholm crowd incensed.
Former Gloucester full back Willie Walker levelled scores after 24 minutes as Gloucester left hands in the ruck before both captains received a lengthy lecture as the lectures continued.
The game was becoming a real contrast in styles with Gloucester trying to move the ball wide whereas Worcester were using their powerful pack to punch holes around the fringes.
As the half wore on, Worcester's tactics began to pay off and number eight Nateni Talei was at the heart of all things good for the men from Sixways.
His initial break almost put centre Dale Rasmussen in for the game's first try. Gloucester hauled him down inches short but hooker Scott Lawson killed the ball and was promptly sinbinned. Walked kicked the penalty for 3-6.
And, as time expired, Talei stunned Kingsholm. Spencer tried to mix things up with a grubber but Greg Rawlinson covered well and offloaded to the galloping Talei who slipped a despairing tackle before romping home from halfway. Walker's conversion made it 3-13 at half time and Dean Ryan had some team talk to deliver.
Gloucester so desperately needed a score, or just a bit of luck and thought they had it when Worcester scrum half Ryan Powell was caught in possession in his own 22.
The pressure built but Worcester didn't break until Olly Morgan tried a grubber near the line and was crudely blocked by flanker Tom Wood. Referee Debney waved the yellow card and surely Gloucester's moment had come?
Sadly not. If anything, 14 Worcester men played better than 15. In fact, Worcester almost snatched a further score but Willie Walker pushed an attempted drop goal and then a penalty attempt wide of the right hand post.
In a bid to influence the game, Ryan started to use his bench and started sending on the reinforcements after only 45 minutes.
Scrum half Rory Lawson and flanker Apo Satala made the most impact, Lawson sniping around the fringes and posing questions while Satala carried with purpose.
But there was no breaking Worcester down. Openings out wide were created but the drift defence got across. When Gloucester straightened the line and carried into contact, Worcester often won possession on the floor when they had no right to.
Barkley got Gloucester back within bonus point range with a 52nd minute penalty after Rory Lawson was tackled too early after a quick tap penalty.
Both captains were lectured - again - and Debney's patience ran out when Marco Bortolami and Greg Rawlinson scuffled and were despatched to the sin bin to cool down.
The sense that it just wasn't going to be Gloucester's night grew as the countdown clock headed inexorably towards zero.
Barkley struck the post with a penalty from wide right and the rebound fell to the Worcester defence and Satala so nearly forced his way over but was gang tackled into touch at the corner flag.
The Cherry and Whites seemed to spend the whole of the last ten minutes hammering away in the Worcester 22 but not a tackle was missed.
Olly Morgan came closest, tackled just short of the line. His attempted offload hit the ground and Gloucester's hopes ebbed away.