Wasps suffer first defeat in seven matches as Greig Laidlaw stars for Gloucester
Wasps suffered a first Aviva Premiership defeat for two months as Gloucester continued an impressive push towards the play-off places.
Gloucester's fourth win in their last five league starts was achieved against the odds after they lost four players - two of them on stretchers - to injuries as Rob Cook, Henry Purdy, Paddy McAllister and Billy Burns all went off.
Scotland and Gloucester captain Greig Laidlaw's second-half penalty secured a 13-10 verdict, which came after an earlier penalty and his conversion of hooker Richard Hibbard's try.
Wing Christian Wade scored a memorable solo try for Wasps, with fly-half Jimmy Gopperth adding a conversion and penalty, before Gopperth sent a drop-goal attempt narrowly wide with the final act of an absorbing game.
Wasps' run of six successive Premiership wins came to an end, even if a losing bonus point provided some consolation, as they reflected on a first league defeat since January 2.
Gloucester did a superb job of stopping Wasps' free-flowing style at source, hunting down attackers and defending resolutely, with lock Jeremy Thrush and number eight Ross Moriarty delivering outstanding displays.
Wasps, apart from the elusive Wade's flash of brilliance, never seriously looked like breaking Gloucester down, which was a huge tribute to the home side, given how several teams have felt the Coventry-based club's full attacking force this season.
Centre Billy Twelvetrees also produced a high-class performance, marshalling Gloucester's back-line defence magnificently, and however hard Wasps tried, they could not find way through.
Laidlaw returned from Six Nations duty to replace Willi Heinz, who went off during last Saturday's comfortable win against Newcastle because of calf muscle trouble, while three changes up-front saw starts for Tom Savage, Sione Kalamofini and Matt Kvesic.
Wasps gave a start to hooker Ed Shervington, with flanker Sam Jones replacing Thomas Young and packing down alongside back-row colleagues George Smith and Nathan Hughes.
Laidlaw kicked Gloucester into a third-minute lead, but the home side then lost full-back Cook, who went off after he was laid low following an attempted tackle on Wasps lock Kearnan Myall.
Wasps could not emerge from their own half, pinned back through a combination of astute tactical kicking by Gloucester's half-backs and an eagerness of the home threequarters to attack space, and that domination was rewarded with an 18th-minute try.
Wasps defended aggressively in organised fashion, yet they were finally undone from close range when Hibbard powered over and Laidlaw added the conversion for a 10-point advantage.
Gopperth opened the visitors' account when he kicked a penalty two minutes later, but it was to Gloucester's credit that they conceded no further points before half-time despite suffering two more injury blows.
Wing Purdy limped off to be replaced by Henry Trinder, then prop Yann Thomas took over from McAllister, who was carried off after appearing to suffer a serious leg injury.
There was a far greater sense of urgency about Wasps at the start of the second half, and they required barely three minutes to draw level as Wade left Gloucester's defence in tatters.
The England international received possession just inside his own half, and then left four would-be Gloucester tacklers floundering before completing his run with a celebratory dive.
Gopperth kicked the conversion to make it 10-10, and Gloucester, after dominating the contest, suddenly found themselves in retreat, but they coped well with Wasps' power-game before another Laidlaw penalty edged them back in front.
Burns' departure meant that Gloucester's injury woes continued midway through the final quarter, yet they closed out the game magnificently, keeping Wasps at bay and claiming another important four points that keeps them challenging strongly amid a congested Premiership mid-table.