Niall Scannell, Tommy O'Donnell and Rory Scannell were also on the scoresheet for the Irish province, while replacement James Cronin added a brace.

Hooker Scannell touched down off a maul to put the visitors ahead inside three minutes in Parma before flanker O'Donnell made Zebre pay for conceding three consecutive penalties by crossing 15 minutes later.

O'Mahony's first try of the afternoon extended the lead with 26 minutes on the clock.

The Italian side, who have never beaten Munster in the PRO12, responded through Derick Minnie's converted try on the half-hour mark, before Munster fly-half Tyler Bleyendaal, who converted the opening three tries, added a penalty in the final minute of the first half.

Munster centre Scannell joined his older brother on the scoreboard with the first try of the second half to ensure his side a bonus point, before O'Mahony secured his brace after Marcello Violi was sin-binned for the hosts.

Despite their numerical disadvantage, Zebre reduced the deficit to 12 points through a converted try from South African Lloyd Greeff with just under 25 minutes to play.

Munster quickly reasserted their authority, though, as Cronin marked his comeback from injury by putting the result beyond doubt with two tries in the final 20 minutes, both converted by Rory Scannell.

Prop Cronin, a replacement for David Kilcoyne, crossed the whitewash for the first time in the 62nd minute before adding another 10 minutes later as the visitors inflicted a 16th defeat of the campaign on their struggling hosts.