Results from the weekend mean that three out of the four semi-finalists for the Heineken Cup play their domestic rugby in the Magners League, the first time the League has had such representation at this stage of the northern hemisphere's most prestigious competition.
It is also the first time teams from the Celtic Unions have taken up the majority of the semi-final berths since the inaugural season of the Heineken Cup when neither England nor Scotland entered sides.
For current European champions, Munster, it will be their eighth semi-final appearance in ten years, whilst their opponents in the mouth watering all-Ireland tie, Leinster, make it to this stage for the fourth time, although they have never lifted the trophy.
Cardiff Blues, who next week face Gloucester in the Anglo-Welsh EDF Energy Cup at Twickenham, reached the semi finals for the first time since the region was formed with a 9-6 victory over French aces Touluse, however their forerunners, Cardiff, played in the very first Heineken Cup final at the Arms Park.
Director of Celtic Rugby, David Jordan said "Congratulations must go to all the teams for their performance over the weekend, a clear reflection of the success that Magners League teams, and their players now enjoy when they transcend into other tournaments.
"With the RBS Six Nations Trophy once more safely secured in Celtic hands, there is now all to play for to ensure that the Heineken and EDF Energy Cups will both be retained by Magners League teams. Good luck to all those taking part."
Carmarthen Quins are holding an exhibition to commemorate club players who fought in World War I. All welcome to the clubhouse on Friday afternoon to learn more about local history, or share any family anecdotes or artifacts.