Hugo Keenan enjoyed a dream start to his test career as he scored two tries in the opening 40 minutes of his debut.
He scored his first try on the half hour mark before he was denied a second due to obstruction by James Ryan.
However, he did manage to grab another before half time as Will Connors and Caelon Doris made a turnover inside their 22.
Conor Murray then broke through the defence and looked to have gone the wrong way before putting in an excellent kick to set up Keenan for his second try.
CJ Stander got the try-scoring underway for Ireland as he forced his way over the line in the 8th minute after an early scare from Italy as they broke through the defence and Paolo Garbisi slotted a penalty as Conor Murray was sent to the sin bin.
Ireland managed to keep Italy out for the remainder of the half to lead 24-3.
Keenan is only the fifth player in Irish 5/6 Nations history to score a brace in his in the competition, after John Arigho in 1928, Bertie O'Hanlon in 1947, Seamus Byrne in 1953 and John Kelly in 2002.
He is also the first man to score two tries on his Ireland debut since Dave Kearney crossed twice against Samoa in 2013.