Wasps were dumped out of the Heineken Cup as Ronan O'Gara led Munster to a thumping victory in treacherous conditions at Thomond Park.

The holders would have progressed to the quarter-finals with a draw but ultimately could not even claim the losing bonus point that guaranteed second place in Pool Five.

Clermont's rout of Llanelli ensured the French club finished second, ending Wasps' hoping of sneaking through to the last eight via the back door.

Instead, Munster topped the pool to reach the knockout stages for a unprecedented 10th successive season where they will face either Gloucester or Toulouse.

Torrential rain made the match a lottery for much of a finely-poised first half but Munster seized control after the interval to flatten the holders.

Ronan O'Gara spearheaded the 2006 Heineken Cup champions' assault with a flawless 14-point haul comprising of four penalties and a conversion.

But the outcome - and Wasps' fate - was sealed by Denis Leamy's 76th minute try, inevitably created by the outstanding O'Gara.

Wasps fly-half Danny Cipriani produced a mature display that should have convinced England head coach Brian Ashton that he is ready to play a role in the RBS 6 Nations.

Cipriani accounted for Wasps' solitary score with a long-range three points and his kicking out of hand was impressive throughout.

But it was not all good news for Ashton whose preparations for the Six Nations have been hit by an injury to Simon Shaw.

Second row Shaw was stretchered from the pitch in the 49th minute after falling awkwardly and was immediately taken to hospital.

He joins England team-mate Paul Sackey on the sidelines after the winger was forced out of tonight's do-or-die showdown with an abscess and a viral infection.

Wasps shrugged off the late loss of Sackey to establish early dominance that was rewarded by a Cipriani penalty.

They were somewhat lucky to receive the shot at goal, however, as referee Nigel Owens had missed a forward pass from Eoin Reddan to Lawrence Dallaglio in the build-up.

But Munster, who had built up a head of steam through their pack, struck back when Cipriani strayed offside and O'Gara nailed the three points.

The Ireland fly-half then saved a certain Wasps try in the 15th minute as he sprinted back to fend away David Doherty's chip ahead after the winger had been sent dashing into space by Fraser Waters.

Dallaglio and Leamy were warned by Owens when a small fight erupted and the Welsh official continued to be involved as the match grew increasingly fractious.

Leamy was harshly sent to the sin bin in the 23rd minute for stripping the ball from Wasps when on the ground but shortly after the champions were penalised as they pounded away at the line.

The wet conditions made open play a lottery with both teams spilling the ball freely while a pair of loose kicks from Cipriani and O'Gara added further unpredictability to proceedings.

Shaw was shown a yellow card for not retreating 10 yards at a free-kick and O'Gara punished the infringement to send Munster 6-3 ahead.

A blunder by Dominic Waldouck allowed Munster to pour forward and force the penalty that O'Gara landed from out wide to put his side in the driving seat at half-time.

Shaw's night was ended when he tumbled beneath a melee of players early in the second half, requiring lengthy treatment, and Wasps' problems continued with the sin binning of Dallaglio.

The number eight, playing his last Heineken Cup match ahead of retirement at the end of the season, freed the ball while grounded and Owens brandished the yellow card.

O'Gara obliged with the penalty and Wasps, trailing 12-3 and playing into the wind, were fading from the contest.

And their challenge was effectively over in the 75th minute when Leamy sprinted over after O'Gara had spotted a gap and exploited it with a perfectly executed run.

O'Gara slotted the conversion and there was no respite for Wasps, who remained under the cosh until the final whistle.