Munster made it two wins from two under new head coach Clayton McMillan on Saturday night.
Ruadhan Quinn, Gavin Coombes and Diarmuid Barron went over for tries in their 23-20 victory over Cardiff in the United Rugby Championship.
A Jack Crowley penalty and drop goal in the closing quarter proved crucial for the reds at Thomond Park.
Next up is the visit of Edinburgh to Cork on Friday.
Leinster have opened a league campaign with successive losses for the first time in 23 years, they were beaten 39-21 by the Bulls in South Africa.
