Zurich Premiership leaders Gloucester paid for the price for lock Adam Eustace's early sending off as they went down to their first defeat of the season.

Nigel Melville's side did not go down without a fight against his former club but Eustace's fourth-minute dismissal for stamping on Wasps fly-half Alex King proved too much of a handicap.

The gaps eventually opened up allowing Wasps to maintain their unbeaten home record since moving to Wycombe's Adams Park with tries from Mark van Gisbergen, Josh Lewsey and Simon Shaw.

They swung the match after Gloucester fly-half Ludovic Mercier had cancelled out a King penalty and then converted after centre Terry Fanolua had raced in near the posts.

Van Gisbergen was only on the pitch for 12 minutes in the first half as a blood replacement for centre Ayoola Erinle but it was long enough for him to take a short pass from hooker Phil Greening and go over in the left corner.

That cut the deficit to two points but Wasps had to defend stoutly to prevent Gloucester from pulling away as both Greening and Lewsey prevented speedy winger James Simpson-Daniel from scoring tries with superb tackles.

King, who had failed to convert van Gisbergen's try and then missed a simple penalty, suffered a far worse misfortune just before half-time when he sustained a head injury.

As the players trooped to the dressing room he was attended on the pitch for five minutes by medics before being taken to hospital for observation.

Wasps soon made the extra man tell at the start of the second half and early pressure brought a penalty for Kenny Logan, who took over the goal kicking duties from King.

He also converted from wide out when Lewsey capitalised on a perfectly-timed pass form former Wales scrum-half Rob Howley to race in for a 46th minute try.

Howley, prompting and probing all afternoon demonstrated just why Melville had picked him out as the dangerman to his Gloucester side and questioned the timing of his decision to quit international rugby.

Mercier cut Wasps' lead to five points with a penalty but victory was sealed in the 70th minute when van Gisbergen, who began his second spell as King's replacement, put the pressure on for big lock Simon Shaw to power over.

Both Shaw and Gloucester's Mark Cornwell were sin-binned in the closing stages but Gloucester were determined not to go down without a struggle.

They came back to put Wasps on the defensive in the closing stages and salvaged a point with full-back Henry Paul's injury-time penalty cutting the deficit to seven points.

Wasps:

Tries: van Gisbergen, Lewsey, Shaw.

Cons: Logan.

Pens: A. King, Logan.

Wasps: Lewsey, Roiser, Abbott, Erinle, Logan, A. King, Howley, Dowd, Greening, W. Green, Shaw, Birkett, Worsley, Volley, Dallaglio.

Not Used: Wood, van Gisbergen, Rudd, Scrivener, Beardshaw, Molloy, Leota.

Sin Bin: Dallaglio (52), Shaw (80).

Gloucester:

Tries: Fanolua. Cons: Mercier.

Pens: Mercier 2, Paul.

Gloucester: Paul, Garvey, Fanolua, Todd, Simpson-Daniel, Mercier, Gomarsall, Woodman, Azam, Vickery, Eustace, Cornwell, Boer, Forrester, Paramore.

Not Used: Amor, Stuart-Smith, Delport, Deacon, Fortey, Buxton, Pearce.

Sin Bin: Cornwell (79).

Sent Off: Eustace (4).

Att: 8,768

Ref: N Williams (WRFU).