Keith Earls and Conor Murray dotted down for second-half tries as Ireland were made to work for their victory in Rome.
Quinn Roux had powered over to give the champions an early advantage, the lock’s finish coming after 19 phases.
Jacob Stockdale then raced clear shortly after for a trademark second as Joe Schmidt’s side threatened to run away with it.
But back came Italy, and Edoardo Padovani collected a superb Tommaso Allan pass to reduce the deficit.
Better was to come for the hosts as centre Luca Morisi finished in the corner to hand them the half-time lead following superb play from scrum-half Tito Tebaldi.
Ireland, though, took control after the break, Earls brilliantly dancing past two Italian defenders to touch down.
And on his 70th Test start for his nation, Murray took advantage of a powerful driving lineout to put the final nail in the Italian coffin.