Wasps preserved their slim chance of Heineken Cup qualification next season - but an emphatic victory over bottom club Bristol came at a cost.

England internationals Paul Sackey and Tom Rees both went off injured during the first half of a seven-try Guinness Premiership encounter.

It did not look good for either player, with their latest setbacks during injury-hit seasons coming only two days before Wasps boss Ian McGeechan announces the Lions squad to tour South Africa this summer.

Lions watchers gleaned little from the Memorial Stadium action, although both fly-half Danny Cipriani and lock Simon Shaw did their best to nudge McGeechan.

Cipriani scored Wasps' decisive second try - he also slotted four conversions and a penalty - while Shaw delivered a workaholic contribution in the loose.

But Wasps, having surrendered their Premiership title almost three weeks ago, still look unlikely to make the English cut for Europe.

They must beat Gloucester next weekend to have any hope of finishing seventh, yet that still would not be enough if semi-finalists Northampton, Saracens or Worcester win the European Challenge Cup next month.

And Wasps can have few complaints if they fail to qualify, having won only 10 of their 21 Premiership games this term.

Wing Josh Lewsey, scrum-half Joe Simpson (2) and flanker Serge Betsen also added tries for the visitors - Simpson's first was a superb 60-metre solo effort - with Bristol restricted to a couple of Ed Barnes penalties before substitute forward James Phillips and wing Lee Robinson bagged late touchdowns, with Barnes adding one conversion.

Relegated Bristol welcomed back internationals David Lemi and Shaun Perry for their final Premiership home game before exiting English rugby's top flight.

But Wasps were again without former England captain and Lions squad candidate Phil Vickery, whose anticipated return from concussion was further delayed.

And there were further fitness problems for Sackey, as his comeback following a calf muscle injury lasted only nine minutes.

Sackey hobbled out of the action on his first appearance since the RBS 6 Nations Championship, having made one powerful run that set up a try-scoring platform, which was subsequently wasted by Cipriani's forward pass to an unmarked Shaw.

Barnes and Cipriani then exchanged penalties but the half was punctuated by several injuries.

Bristol prop Wayne Thompson and Wasps tighthead Pat Barnard both required treatment for cuts, while Wasps lost Rees seven minutes before the break.

The flanker, visibly in pain, walked gingerly away nursing what appeared to be an arm or shoulder injury and he was replaced by John Hart.

Rees and centre Dominic Waldouck had been Wasps' most influential players and, after Barnes edged Bristol back in front through a second penalty, the visitors struck.

Waldouck made his third clear break of the first 40 minutes and, on this occasion, Wasps capitalised, with Lewsey providing a high-class finish in the corner.

Cipriani drifted the touchline conversion attempt wide but, although Wasps deserved their 8-6 interval advantage, it should have been more after they dominated territory and possession.

Cipriani, though, needed less than two minutes after the restart to send Wasps on their way towards an ultimately comfortable win.

Betsen's excellent approach work created space for attackers either side of him and Cipriani powered over despite being marshalled by two Bristol defenders.

He added the conversion and also slotted the extras 12 minutes later when Simpson - last year's England Under-20 World Cup scrum-half - scored after setting off on a run from 10 metres inside his own half.

It finished Bristol and, although they bravely sought a consolation try during the closing quarter, Wasps almost added a bonus-point touchdown.

A long lineout throw in the shadow of their own posts went straight to centre Riki Flutey, whose deft pass sent Cipriani away on a marathon solo dash.

He backed himself to make it but Bristol substitute Tom Arscott shadowed him cleverly before making a try-saving tackle.

The all-important fourth Wasps touchdown, though, arrived 12 minutes from time when Simpson pounced for his second score and Betsen then crossed to compound Bristol's misery.

Two more successful Cipriani conversions meant he finished with a personal tally of 16 points as Wasps enjoyed themselves in the sunshine, although Phillips and Robinson at least ensured Bristol also had some fun.