The Heineken Cup takes centre stage this weekend with most rugby betting pundits tipping Munster to clinch a third title in four seasons.
The inconsistent Ospreys travel to Thomond Park on Sunday to face a team that is in the knockout stages of the competition for a record 11th successive season.
Munster's recent Heineken Cup record is unsurpassed. They beat Toulouse 16-13 in last year's Final and edged past Biarritz 23-19 in 2006.
Their only blemish in the last four years came in the 2007 quarter-finals when they lost 24-15 to Llanelli Scarlets.
Munster should progress after easing to victory against Leinster last weekend to cement their place at the top of the Magners League table.
Key men like Frankie Sheahan and Rua Tipoki are missing but Tony McGahan's team should have far too much strength for an Ospreys side that could be without Lee Byrne.
They are also without Gavin Henson although lock Ian Gough is expected to recover from injury in time to feature.
The only other Welsh side in the last eight are Cardiff Blues and they can expect a tough encounter when they take on three-times winners Toulouse.
Last year's beaten finalists edged past Cardiff in the first European Cup Final in 1996 and went on to beat Perpignan 22-17 seven years later and Stade Francais in 2005.
The Blues already have an EDF Cup Final appearance to look forward to next week when they take on Gloucester and are expecting to attract their biggest ever crowd for the Toulouse game.
More than 30,000 people are expected to be at the Millennium Stadium but all the signs point to a Toulouse win.
English rugby is on the up again following a spirited Six Nations campaign and one Guinness Premiership side will definitely be in the semi-finals as Leicester take on Bath.
The Tigers should progress to the last four as they have home advantage and can boast a better record in the competition.
They won two successive European Cups at the start of the millennium and have also been beaten finalists on two occasions, the last in 2007 when they lost to Wasps.
Bath beat Brive in 1998, their only Final appearance, but they have been boosted by the news that Butch James is available after being cleared of a stamping charge while Michael Claasens returns from injury.
Leicester will be without Julian White after he was suspended for punching Andrew Sheridan and former England captain Martin Corry while Aaron Mauger is rated 50-50.
There could be two English sides in the semi-finals as in-form Harlequins take on Leinster at the Stoop.
Leinster's side is full of Ireland internationals including Brian O'Driscoll, Luke Fitzgerald and Shane Horgan and they are second in the Magners League.
However, they will be without Jonathan Sexton who is serving a two-game ban following an incident against Munster.
Quins have no pedigree in this competition but Dean Richards' side have hit form at exactly the right time and could shock Leinster on Sunday.