Munster scored three converted tries in the final 10 minutes to break clear of London Irish and earn a confidence-boosting 28-14 bonus-point win.
Irish were just 12 minutes away from becoming only the second team to beat Munster in a Heineken Cup tie at Thomond Park.
Their captain Seilala Mapusua scored a try and set up the second for Sailosi Tagicakibau as the visitors edged into a 14-7 lead. But Munster, who are Amlin Challenge Cup-bound now, hit back decisively with late tries from Niall Ronan, Keith Earls and replacement Darragh Hurley.
That closing barrage of points put a gloss on the final scoreline, but Munster can take heart from how they raised their game when staring at a possible third pool defeat.