While 2006 and 2008 champions Munster are appearing in a record equalling 13th quarter-final, 1999 winners Ulster are in the knock-out stages for only the third time in 17 seasons.
They went down to Northampton Saints in last season's quarter-finals and went through this time as a Pool runner-up and the No 8 ranked qualifier. Paul O'Connell, the inspirational Munster captain, has made a timely return from injury and the line-out contest involving O'Connell and Ulster skipper Johann Muller could be a key battle.
Muller is joined in the Ulster squad by fellow Springboks scrum half Ruan Pienaar and back rower Pedrie Wannenburg, plus All Blacks prop John Afoa, while Munster can boast eight of the players who featured for Ireland in the 2012 RBS 6 Nations.
Although this is the first Heineken Cup meeting between the clubs they know just about all there is to know about each other's games through the Pro12 and it is sure to be a tight affair up front. Outside half Ronan O'Gara has scored a record 1,287 Heineken Cup points in 103 appearances and his No 10 head-to-head with Ian Humphreys will also be crucial.
Munster have lost just two Heineken Cup matches at their Thomond Park fortress, to Cardiff back in 1998 and Leicester Tigers in 2007, and will be out to make their home advantage count yet again with the winner taking on either Edinburgh or Toulouse in the semi-finals.