The former Newcastle player landed five penalties and a conversion for a vital 17-point haul.

He also produced the terrific defence-splitting run which laid on the 47th-minute try for centre Riki Flutey, who effectively ensured victory against the club he left last summer.

It was Walder's second successive 100% kicking performance following his 19-point contribution to last weekend's 29-25 victory over Harlequins in another London derby.

Irish replied with tries from full-back Peter Hewat and left-wing Sailosi Tagicakibau with fly-half Eoghan Hickey kicking two penalties.

But the home side paid the price for the penalties they conceded to Walder.

The St Patrick's weekend fixture attracted a record crowd for a GUINNESS PREMIERSHIP match on a club ground.

The 23,709 attendance at Reading's Madejski Stadium has only previously been surpassed for league matches played at Twickenham.

Irish had the fans on their feet as they stunned Wasps with Hewat's second-minute try.

Hooker David Paice, centre Seilala Mapusua and Tagicakibau moved the ball quickly before Hewat went past Mark van Gisbergen to touch down.

An intriguing forward battle saw first Irish and then Wasps both spend lengthy spells pressuring the try-line but both sides defended stoutly to hold out.

The Wasps pack did manage to force their way over the Irish line in the first half but referee Rob Debney ruled that they had failed to ground the ball after consulting the fourth official for a video replay.

Wasps took the lead for the first time when Walder kicked his third penalty on the stroke of half-time to put them 9-8 ahead.

Irish were always chasing the game after Flutey scored Wasps' only try of the match in the 47th minute, with Walder adding the conversion before increasing their advantage to 19-8 with another penalty.

Irish squandered a golden opportunity for a second try in the 65th minute when flanker Declan Danaher, out on the right wing, dropped Mapusua's final pass with the line at his mercy.

But the home side refused to give up hope and they struck again two minutes later after right-wing Topsy Ojo produced a superb diagonal run from inside his own half.

Ojo was stopped 15 metres short by the Wasps cover following his scything run which took him past three players, but he released the ball for the unmarked Tagicakibau to cross in the left-hand corner.

Walder struck his fifth penalty but, with a minute to go Hickey responded with a long-range penalty from a difficult angle on the left to secure the consolation of a losing bonus point for Irish.