Apart from two tries in the second half, by Boeta Chamberlain (flyhalf) and Yaw Penxe (wing), it was a tough baptism for the Cell C Sharks against one of the best teams in the competition.
The KwaZulu-Natalians defended very well, with a tackle success rate of 93%, but their discipline let them down as they conceded 17 penalties to the seven of Munster.
And to add to their woes, Springbok prop Thomas du Toit - who had a short stint with Munster a few seasons ago - was yellow carded just before the half-hour mark for repeated infringements.
The Durbanites, who started well but had nothing to show for it on the score board, conceded only one try in the time Du Toit was in the sin bin, but against a slick outfit like Munster, it was far from ideal.
Zebo, who recently moved back to Munster from France where he was playing for Racing 92, celebrated his return to Thomond Park in style, scoring in the fifth and 79th minutes.
Just before Zebo crossed for his second, former Southern Kings loose forward Chris Cloete bagged Munster's fifth try to give the hosts' score a bit of a boost.
Chamberlain's intercept try in the 56th minute and a brilliant move down the left flank, where Jeremy Ward's perfect offload allowed Penxe to race away, were the only highlights for the Cell C Sharks.
Munster 42 (20) - Tries: Simon Zebo (2), Craig Casey, Gavin Coombes (2), Chris Cloete. Conversions: Joey Carbery (2), Ben Healy. Penalty goals: Carbery, Healy.
Cell C Sharks 17 (3) - Tries: Boeta Chamberlain, Yaw Penxe. Conversions: Curwin Bosch (2). Penalty goal: Bosch.