Toby Faletau produced a barnstorming performance to ensure that his former Lions coach Graham Rowntree made a losing start to his first competitive match as Munster boss.
Munster at least escaped from the Arms Park with a losing bonus point after Jarrod Evans failed to convert the clinching try from Aled Summerhill two minutes from time.
But Munster and Rowntree could have few complaints as they fell to their first defeat at the Arms Park in four years.
