View the match highlights here.
It was Munster's sixth PRO12 win in a row and their second Welsh win on the bounce after the previous week's win against Cardiff Blues.
Ian Keatley kicked all 18 of Munster's points including two late penalties to secure the win.
Head Coach Rob Penney was pleased that his side kept their winning run going.
"I'm really delighted to get 9 points out of the last two weeks, it has been a real bonus for us," he said.
"The lads have worked really hard coming out of Cardiff last week with a six day turnaround and travel again, and it's a great credit to the guys to get the job done."
Next up for Munster is a Heineken Cup double-header against Perpignan, starting at Thomond Park next Sunday (ko 12:45pm). Tickets are on sale for the game online here, from the Munster Rugby ticket offices in Musgrave Park and Thomond Park or by calling 0818 365 555.