Gloucester revived their Zurich Premiership play-off hopes and put a dent in Wasps' title ambitions by winning an absorbing encounter at Kingsholm.

Wasps' defeat - their first Premiership loss for 12 games - means that Bath are guaranteed top spot in the 'regular' league season if they beat Harlequins on Sunday and secure a bonus point.

First place secures an invitation to the Premiership play-off final at Twickenham on May 29, and Wasps, who have won one game less than Bath, will not be able to overhaul their rivals in the event of a five-point West Country triumph against Quins.

If that scenario does not unfold, then it will all boil down to next weekend's final round of games when Wasps host Leicester and Bath entertain Gloucester.

Wasps now look destined to finish second - and a play-off semi-final clash at home to either Gloucester or Northampton in a fortnight's time.

Gloucester, courtesy of an outstanding success secured through tries by James Simpson-Daniel, Marcel Garvey and Andy Hazell, moved above Northampton into third, but Saints will reclaim that berth with victory over Leeds tomorrow.

Gloucester avenged their 34-3 Heineken Cup quarter-final thumping by Wasps three weeks ago, but injury time tries from wing Kenny Logan and substitute centre Mark Denney at least gave the visitors a losing bonus point.

The day ended on a sour note for Wasps though, when their ex-All Blacks prop and revered scrummager Craig Dowd was stretchered off nursing what appeared to be a serious leg injury.

Wasps fielded 10 of the starting line-up that accounted for Heineken Cup semi-final opponents Munster in a Lansdowne Road epic last weekend, including England trio Lawrence Dallaglio, Joe Worsley and Stuart Abbott.

Gloucester, meanwhile, paid tribute to 38-year-old prop Andy Deacon on his final Premiership appearance at Kingsholm, and he received a rapturous reception from a capacity crowd when he led the home side out.

Deacon and his fellow forwards made all the early running, and an outside break from centre Henry Paul almost led to a try, but Garvey dropped Paul's inside pass.

Paul though, booted a fourth-minute penalty, giving Wasps plenty to think about, especially when Dallaglio departed for treatment on a bloodied mouth.

Gloucester were an initial step ahead in thought and deed, yet they kicked away several promising opportunities, with Paul and scrum-half Andy Gomarsall both proving glaring guilty parties.

Dallaglio returned - it appeared that he took an accidental stray boot in the face - in time to witness Paul's second successful penalty, before Paul and Wasps full-back Mark Van Gisbergen missed penalty chances in quick succession.

Wasps, despite competing aggressively up-front, fell further behind when Gloucester sliced open their midfield defence nine minutes before the break.

The home side secured turnover possession, and fly-half Duncan McRae weaved his way clear in effortless fashion before giving Simpson-Daniel a simple scoring pass. Paul's conversion put Wasps in deep trouble at 13-0 adrift, although McRae's opposite number Alex King immediately slotted a penalty.

Gloucester thought they had broken through again on 39 minutes, but referee Tony Spreadbury called back centre Terry Fanolua after he received a forward pass.

And Wasps reduced their arrears within seconds, as McRae's intended pass to Paul was intercepted by centre Fraser Waters, who trotted over unopposed. King's conversion made it 13-10 at half-time.

Gloucester boss Nigel Melville made a half-time substitution, sending on flanker Andy Hazell instead of Peter Buxton, and after absorbing concerted Wasps pressure, the home side moved 16-10 ahead when Paul completed his penalty hat-trick.

Both teams were guilty of errors as the tension increased, yet Gloucester's forwards continued to relish the ferocious physical exchanges, securing a territorial edge.

Wasps' star scrum-half Rob Howley joined the action as a 52nd-minute substitute, but Gloucester's response was to increase their lead.

Simpson-Daniel went close to claiming his second touchdown, yet Gloucester were not to be denied, and number eight Junior Paramore delivered a scoring pass to Garvey, who dived over wide out.

Referee Spreadbury required confirmation from the video official, but the try was awarded and Gloucester led 21-10 approaching the hour-mark.

King's second penalty gave Wasps a glimmer of hope on 65 minutes, but Gloucester killed them off by claiming their third try.

More quality work from the forwards left Wasps unable to cope, and Hazell dived over wide out. Paul effortlessly kicked the touchline conversion and Gloucester were coasting at 28-13 ahead.

Wasps scored late tries from Logan and Mark Denney, one of which King converted, but they arrived too late and their first league defeat since Leicester beat them on November 8 was sealed.

Teams;

Gloucester: Van der bergh, Garvey, Fanolua, Paul, Simpson-Daniel, McRae, Gomarsall, Woodman, Fortey, Deacon, Cornwell, Brown, Boer, Buxton, Paramore.

Replacements: Todd for Fanolua (72), Dupreez for Fortey (77), Eustace for Cornwell (65), Hazell for Buxton (41).

Not Used: Roncero, Wood, Amor.

Tries: Simpson-Daniel, Garvey, Hazell.

Cons: Paul 2.

Pens: Paul 3.

Wasps: van Gisbergen, Voyce, Waters, Abbott, Logan, A. King, Richards, Payne, Leota, Green, Purdy, Birkett, Worsley, Volley, Dallaglio.

Replacements: Denney for Waters (69), Erinle for Abbott (69), Howley for Richards (53), Gotting for Leota (69), Hart for Birkett (69), Lock for Volley (69).

Not Used: Dowd.

Tries: Waters, Logan, Denney.

Cons: A. King 2.

Pens: A. King 2.

Att: 11,000

Ref: Tony Spreadbury (RFU).