The tournament champions needed a maximum return against Calvisano at Causeway Stadium to have any hope of reaching the quarter-finals and the bonus point arrived in first-half injury-time through Johnny O’Connor.

With Wasps’ mission accomplished, all eyes turned to Welford Road where Biarritz clinched a shock 21-17 triumph over Leicester to resurrect the competition hopes of Lawrence Dallaglio and co.

The former England skipper must now take his team to the Parc des Sports Aguilera next Saturday where a straight victory against the Pool One leaders could be enough to book their place in the knock-out stages.

Success would prove a remarkable change in fortunes for Wasps given that last month’s two Heineken Cup defeats by Leicester over successive weekends had left their European chances hanging by a thread.

Victory over Calvisano today was never in doubt and the try-fest was just what Wasps needed given that if teams finish level on points, the eventual placings will be settled by the try-count.

O’Connor and Mark van Gisbergen scored a brace each while Josh Lewsey, Craig Dowd, Tom Voyce, Ben Gotting and Dallaglio also touched down in a one-sided match which saw Calvisano’s Giampiero de Carli sent off for fighting.

The wet conditions resulted in a catalogue of early errors from both sides with one promising Calvisano attack – started by number eight Cabinet Elisabeth - coming to an end when the ball was spilt close to Wasps’ line.

Another blockbusting charge from Elisara wreaked further havoc in the home defence and this time the Italians nearly scored but winger Ludovico Nitoglia dropped the ball over the line after being tackled by Michael Roberts.

Calvisano paid for the missed try in the 13th minute when Wasps crossed with Roberts making the initial break before the ball was released right to van Gisbergen who crossed under the posts.

With the possibility of their presence in the quarter-finals being decided by tries scored – and because of the need to claim a try-scoring bonus point today - Wasps neglected to take the conversion, potentially giving them more time to cross the whitewash.

They managed that for a second time when scrum-half Harvey Biljon found Lewsey - selected at outside-centre in answer to the club’s midfield injury problems - and the England star dummied and slipped over from five yards out.

O’Connor claimed the third try in the 33rd minute after capitalising on excellent work from Voyce and Joe Worsley before Calvisano’s slim chances of avoiding a thrashing receded further with the sin-binning of skipper Maurizio Zaffiri.

Wasps wasted little time making their numerical superiority tell with O’Connor emerging from the bottom of a pushover try after second row Richard Birkett had taken a clean catch at the line-out, securing the crucial bonus point.

The Zurich Premiership champions were stunned two minutes after the interval when fine footballing skills from centre Christian Zanoletti set up a try for Nitoglia in the corner and the winger showed Wasps’ cover a clean pair of heels.

Fly-half Pablo Canavasio converted but normal service resumed in the 54th minute when Voyce scampered over 30 yards after breaking from the back of a ruck while good support work from Gotting resulted in Wasps’ seventh try.

Gotting was the centre of attention in the 68th minute but for the wrong reason after being used as a punchbag by substitute de Carli and the Italian prop was shown a straight red card which ended his brief spell on the pitch.

Dallaglio barged his try over, Pino Patelli pulled one back which Zanoletti converted and then Gisbergen bagged the ninth to complete the rout.