England flanker Joe Worsley made a try-scoring return from injury as champions Wasps moved to the top of the Guinness Premiership.

Worsley, hoping to prove his fitness for an England RBS Six Nations recall after missing the autumn internationals, had played only 63 minutes since mid-October because of knee ligament trouble.

But he took only 28 minutes to make a real impression on this top-four clash as he spun off the back of a maul to run in unchallenged for Wasps' second try.

It was the second of a two-try double-strike in a three-minute spell midway through the first half which effectively decided the outcome of a game watched by a bumper New Year's Eve crowd of 18,122 - the biggest London Irish attendance of the season.

Worsley's England team-mate Josh Lewsey, playing in the centre instead of his international position of full-back or wing, had delivered the first of the two tries when a sharp passing move from skipper Lawrence Dallaglio and newly-established England winger Tom Voyce released him on a clear run down the left.

With full-back Mark Van Gisbergen converting both tries and kicking two penalties, Wasps led 20-9 at half-time and, despite a brief second-half revival from Irish they never looked like relinquishing their advantage.

Fly-half Ross Laidlaw, 22, who made a promising Premiership debut, replied with three first-half penalties and finished up with a 14-point haul.

But it was not enough to save Irish from a second defeat in their last 11 matches in all competitions.

The third-placed team, playing their third tough match in the space of 13 days, also gave a debut to 21-year-old blindside flanker Richard Thorpe as they made nine changes to the starting line-up which beat Saracens on Boxing Day.

Both sides made more than their share of errors in the first half but it was Wasps who took a firm grip and pushed home their advantage to secure the bonus point with a fourth try late in the game.

They capitalised on a strong spell of attacking pressure early in the second half when second row George Skivington scooped the final pass off the floor to send in hooker Raphael Ibanez for their third try, with Van Gisbergen again on target.

Irish hit back when second-half replacement Bob Casey powered his way over for their only try in the 54th minute, converted by Laidlaw.

And Wasps were temporarily reduced to 14 men when Dallaglio was sent to the sin-bin for his part in a melee which followed the try.

But Irish failed to capitalise on that man advantage and while Dallaglio was off the pitch, the only scores were a 62nd-minute penalty from Van Gisbergen, followed three minutes later by one in reply from Laidlaw.

Wasps secured the bonus point in the 78th minute when Skivington dived over in the right corner.

Van Gisbergen, who finished with 15 points, saw his conversion attempt rebound from the post.

Defeat ended Irish's five-match run of home victories since their 30-26 loss to Wasps in the Powergen Cup in October.

Wasps' tenure at the top could be a short one with Sale Sharks, the team they have deposed, visiting Bath on Monday.