Gloucester Rugby held on after Greig Laidlaw’s second-half penalty to record their first victory against an in-form Wasps since September 2012.
The Cherry & Whites – who were hit with three first-half injuries – got off to a fast start after a Laidlaw penalty and a converted try from Richard Hibbard with 17 minutes gone.
Jimmy Gopperth responded from the tee before Christian Wade’s explosive effort levelled the scores early in the second half, but Gloucester kept firm after Laidlaw struck again in the 55th minute.
The visitors pushed but, at the death, Gopperth was off-target with an attempted drop-goal to the delight of Kingsholm.
Wasps had dropped just three possible points in their last six Aviva Premiership Rugby games but it was Gloucester who were on top from the get-go.
And when former Kingsholm favourite Dan Robson fumbled forward, the Cherry & Whites eventually won the penalty that saw Scotland skipper Laidlaw put the first three points on the board.
Dai Young’s men were struggling to find their rhythm, though one promising Frank Halai break was a reminder of how dangerous they could be.
Meanwhile Gloucester continued to win the battle up front and when Jeremy Thrush caused menace at one particular maul, it laid the platform for the opening try.
After a period of sustained pressure in Wasps’ 22, Hibbard finally barrelled over from short range for his second Aviva Premiership Rugby score of the season and Laidlaw completed a simple conversion.
Straight from kick-off Christian Wade ran it back at the hosts and he combined with Rob Miller only for some staunch Gloucester defence to hold the latter up.
It came back for penalty advantage however and, with 20 minutes gone, Gopperth’s kick got Wasps off the mark.
Both teams had try-scoring chances in the next quarter – Wade putting in a tackle before the ball could reach last-man Charlie Sharples, before Nathan Hughes was chased down after bounding clear up the middle.
But Gloucester went into half disappointed to have not extended their lead, as when Wasps were pinged for not releasing, Laidlaw’s effort curved from right to left and missed the posts.
Wasps had the advantage of bringing fresher legs on in the second half, with Gloucester trio Rob Cook, Henry Purdy and Paddy McAllister having already been replaced by Billy Burns, Henry Trinder and Yann Thomas due to injury.
But it took only moments for the visitors to get back level, Sam Jones’ offload sending Wade away and the England winger danced his way up the right touchline before haring over. Gopperth added the extras at a stunned Kingsholm.
Still, Gloucester were still shading it on the balance of things, as Billy Meakes and Matt Kvesic made their presence known with some bustling carries.
And in the 55th minute the hosts were back in front as Laidlaw pushed a penalty between the posts after Wasps failed to roll away.
There was a break in the game for yet another injury – this time Burns needing lengthy treatment – and upon the restart a depleted Gloucester needed a Kvesic turnover to hold Wasps out.
Gloucester steadied the ship but when Laidlaw was presented with another opportunity following a collapsed maul, he missed his second penalty of the afternoon.
Just ten minutes now remained and a dogged Gloucester got their rewards when they saw Gopperth push his drop-goal effort wide with the last action of the match.