Wasps climbed above London Irish to move to fourth place in the Guinness Premiership with a bonus-point victory at Adams Park.
Irish recovered from a shocking start that saw them 13-0 down to contribute to a rousing and hugely physical spectacle. Tom Varndell, Dan Ward-Smith and Dominic Waldouck crossed for Wasps, and they also benefited from an early penalty try, while Seilala Mapusua, Steffon Armitage and James Tideswell responded for Irish.
A derby fixture described by Wasps rugby director Tony Hanks as "fast, furious and usually involving the kitchen sink" had extra edge, with both chasing a top-four finish and a Guinness Premiership play-off semi-final.
Wasps began with internationals Danny Cipriani, Serge Betsen and Paul Sackey on their bench while Irish included veteran player-coach Mike Catt among their replacements. It was also a special day for Wasps and England flanker Joe Worsley, making his 200th appearance.
Irish suffered a controversial penalty-try setback after only three minutes when Armitage hauled down David Lemi off the ball as he chased a grubber-kick up the left by Joe Simpson. Referee Rob Debney decided Lemi would have reached the ball for a try had he not been tackled, sin-binned Armitage and awarded Wasps a penalty try, converted by David Walder.
The decision shook Irish to such an extent that Wasps dominated territory and possession, and Lemi was homing in on the line again when he was tackled by both Paul Hodgson and Ryan Lamb. Wasps were awarded a penalty in the 10th minute after Bob Casey fouled Dan Ward-Smith in the lineout, and Walder made the kick.
A charge up the right by Worsley splintered the Irish defence and sparked a superb attack, halted only when the referee called for medical help for Walder who took a big hit in midfield. But there was no relief for Irish as Wasps kept up the tempo, and it was Debney who made things worse, getting in the way of tackler Kieron Roche when Simpson made a swift break. Irish offended at the breakdown and Walder increased their woes with a penalty in the 16th minute.
Irish launched their first meaningful attack in the 17th minute, and scored a try 60 seconds later. An attack ended with Armitage bundled into touch, but Irish threw the lineout over the back, Steffon Armitage stormed for the line, and after three rucks, Mapusua bored over for the score, converted by Lamb.
Irish should have scored again after a scorching counter-attack sparked by Mapusua, Delon Armitage and Elvis Seveali’i. But Steve Kefu knocked on as Hodgson tried to pass, so Debney sent him to the bin and awarded a penalty, kicked by Lamb.
Back stormed Wasps and Waldouck’s kick up the right was chased by Tom Varndell. Although Delon Armitage looked favourite to win the race, Varndell reached the ball first and scored in the corner. Walder’s attempted conversion sailed wide.
Irish were suddenly matching Wasps. Walder required another bout of treatment after getting clattered in a tackle, and hailstones began falling as Wasps fly-half Walder was replaced by Cipriani after 32 minutes.
Wasps ended the half as they began, on top and scoring a try. Simpson whipped the ball right to Mark van Gisbergen after a surging attack, and his pass out to Ward-Smith was turned into a try by the flag. Wasps lost the impressive Simpson, who suffered a blow to the head, and was replaced for the start of the second half by Warren Fury.
Worsley snuffed out a dangerous Irish attack, led by Mapusua, with a shuddering tackle that left both men sprawled on the deck, breathless. And the fans were equally breathless when Cipriani took a pass from Kefu, changed gears and left Peter Hewat for dead before feeding Waldouck to score Wasps’ third try in the 50th minute.
It was a reminder what England will be losing when Cipriani leaves to play for Melbourne Rebels this summer. His conversion brought up the 30-point mark, and the try meant Wasps had earned a bonus point.
Tempers frayed, but Irish refused to buckle. They stormed the Wasps line in the 54th minute, driven by their pack, and the impressive Steffon Armitage was shunted over for his sixth try in five games. Lamb’s conversion flew wide.
James Tideswell came off the bench in the 70th minute and scored almost immediately. Fury delayed tidying up a loose ball, Tideswell pounced and Tom Homer converted. Cipriani calmed home nerves with a penalty three minutes from time after Peter Hewatt was penalised for a high tackle.