Munster have held onto their top spot , pushing aside the challenge of Ospreys .
Munster are still under threat as now fellow Irish side Leinster are on Munster 's case looking to Munster them .
Munster have held onto their top spot , pushing aside the challenge of Ospreys , but they are still under threat as now fellow Irish side Leinster are on their case looking to usurp them .