Topsy Ojo also scored a 50-metre interception try, but a last-gasp Sam Tuitupou score, who earlier saw yellow for a spear tackle, earned Munster a potentially crucial bonus point.
English champions Leicester needed a late Alesana Tuilagi try to beat underdogs Benetton Treviso 34-29 in Italy.
Chris Burton kicked 16 points for the Italians, while Matt Smith, Craig Newby, Martin Castrogiovanni and Ben Youngs all scored tries for the English side.
The impressive Tomasso Benvenuti bagged two tries before his late drop-goal appeared to have settled matters, but Samoan Tuilagi spared the Tigers' blushes and secured a bonus point.
Saracens were put to the sword 25-10 at French outfit Clermont Auvergne, with unforced errors and missed opportunities undermining a passionate display from the visitors.
Sarries trailed 12-3 at the break, with a lone Derick Hougaard penalty sandwiched between interception tries from Jamie Cudmore, later sin-binned, and Julien Malzieu.
New signing David Strettle crossed over after a slick passing move, with Hougaard converting the extras, but a loose ball fell to Napolioni Nalaga as Sarries searched for a late bonus point, and the Fijian scored a simple try.