England wing Tom Voyce underlined his reputation as one of European rugby's deadliest finishers as favourites Wasps lifted the Powergen Cup at Twickenham.

Ian McGeechan secured a first trophy since succeeding Warren Gatland in Wasps' coaching hot-seat after Voyce's try double underpinned an impressive fightback from 10-3 adrift.

But the Anglo-Welsh showdown will also be remembered for Irish Triple Crown heroes Jonny O'Connor and Simon Easterby being stretchered off as the professional game's high impact nature took its toll during a punishing contest.

O'Connor was taken to hospital for a precautionary scan, while Easterby recovered in time to watch the second half from a touchline seat, yet a 57,000 crowd endured some anxious moments before receiving positive fitness updates over the tannoy system.

English champions Wasps won their fifth successive Twickenham final - three Premiership title play-offs and a Heineken Cup triumph preceded today's victory - and made certain of a Heineken Cup place next term without hitting peak form.

They were guilty of uncharacteristic errors and poor discipline, but Voyce came up trumps when Wasps really needed him to thwart Llanelli's hopes.

Full-back Mark Van Gisbergen added 13 points from the boot and substitute fly-half Alex King slotted a late drop-goal, guaranteeing a failed assignment for Scarlets coach and possible new Wales supremo Gareth Jenkins.

Llanelli had their moments - notably a memorable early try by full-back Barry Davies - yet they left London hugely frustrated at not taking advantage of a Wasps team who did not fire on all cylinders.

Matt Dawson, who will retire from rugby at the end of this season, had to be content with a place on Wasps' bench as McGeechan preferred Irish scrum-half prospect Eoin Reddan.

Llanelli's star number nine Dwayne Peel missed out completely due to a shoulder injury, while fitness problems also ruled out fellow Welsh international Lee Byrne.

The final began in nightmare fashion for Wasps, who saw O'Connor depart after just 48 seconds. He crashed to the turf after smashing head-first into Scarlets number eight Alix Popham, and required five minutes of treatment before being taken away with his neck in a brace.

Samoan Daniel Leo replaced O'Connor, but it was a huge setback for Dallaglio and company, given their tearaway openside's status as a potential Scarlets destroyer.

Things went from bad to worse for Wasps when Llanelli ripped open their much-vaunted defence on 10 minutes.

Scrum-half Clive Stuart-Smith, lock Inoke Afeaki and flanker Gavin Thomas were all heavily involved during a slick build-up, and Davies rekindled memories of a stunning solo score against Heineken Cup opponents Northampton two years ago by skirting outside Van Gisbergen and avoiding Stuart Abbott's despairing defensive lunge.

Fly-half Mike Hercus added the conversion, but then rifled a 40-metre penalty chance wide after referee Alan Lewis marched Wasps backwards following Abbott's show of dissent.

Hercus' second penalty attempt three minutes later hit the post.

When Wasps attacked, they were guilty of an uncharacteristic blunder after Reddan's deft pass was followed by prop Ali McKenzie spurning a clear overlap when he failed to find support runners.

Van Gisbergen looked to have settled Wasps down when he landed a short-range penalty, yet Llanelli's immediate response saw Hercus find his range and secure a 10-3 lead after Lewis warned skippers Lawrence Dallaglio and Easterby about their teams' repeated technical infringing.

But the game was then marred by another alarming incident when Easterby collapsed after trying to tackle Van Gisbergen.

Easterby's team-mate Mark Jones rushed to his aide as play initially went on, turning the Irish forward on to his side before Twickenham's medical crew treated him during a seven-minute stoppage.

It was a shattering blow for the Scarlets, but Wasps remained the team in need of inspiration as McKenzie received a yellow card after he failed to release possession on the floor, confirming Lewis' patience had run out.

Wasps finally got their act together as half-time approached when fly-half Jeremy Staunton intercepted a Stuart-Smith pass and put Voyce over after he lacked the pace to finish off his opportunism, with Van Gisbergen's conversion making it 10-10 at the break following a 57-minute opening period.

The injury outbreak even extended to referee Lewis, who failed to reappear after half-time and was replaced by touch judge Simon McDowell.

Van Gisbergen missed a simple penalty chance and darkening skies illustrated the gloomy mood before a slashing Abbott break - he brushed off Hercus and Davies - lit up Twickenham in creating Voyce's second try.

With his team ahead for the first time, McGeechan summoned reinforcements, sending on Dawson, King and prop Peter Bracken as Wasps belatedly tried moving through the gears.

But heavy rain dampened the closing stages as a spectacle, with King's drop-goal confirming victory and keeping Twickenham's Welsh raiders at bay.