Ronan O'Gara of Ireland attempts to burst through against Italy
Ireland (10) 16
Pens: O'Gara (3)
Italy (3) 11
Pens: Bertolussi (2)
Ireland got off to a winning start in the RBS Six Nations but it was not the convincing performance they hoped for.
They landed the first try in the 18th minute when Ronan O'Gara's crossfield ball was gathered by Andrew Trimble who laid off for Girvan Dempsey to go over.
Italy fought hard and were rewarded with a try by Martin Castrovgiovanni midway through the second half.
O'Gara kicked three penalties to keep Ireland ahead but a late miss caused a nervy last few minutes for the hosts.
Ireland next face France away but will be without centre Gordon D'Arcy who went off in the first half with a stress fracture to his forearm.
Ireland took a while to settle from the kick-off but they nudged ahead with an O'Gara penalty in the 15th minute.
Soon afterwards Eddie O'Sullivan's side stretched their lead with the only try of the first half.
O'Gara's precise kick landed in Trimble's hands and the Ulster winger rode Mauro Bergamasco's tackle before finding Dempsey who dashed home.
The conversion made it 10-0 to Ireland and took O'Gara to 400 points in the Six Nations.
D'Arcy had to go off in the 26th minute after injuring his right arm in tacking Andrea Masi.
That meant Rob Kearney coming on as winger and Trimble switching to inside centre.
Biarritz lock Santiago Dellape was sent to the sin-bin for punching on 30 minutes.
But Italy defended strongly and even produced a penalty through Bortolussi.
Early in the second Ireland had 10 minutes with a man down as Simon Easterby was sin-binned for playing the ball after the tackle.
Italy frequently used cynical measures to halt Irish attacks and one such moment was punished by referee Jonathan Kaplan and O'Gara's kick made it 13-3.
But Ireland were never able to shrug off the dogged Italians and the contest was sparked into life as the visitors got their try on the hour.
Skipper Sergio Parisse was credited with the score after a lengthy deliberation by the television match official, but the number eight subsequently said it had been scored by prop Castrogiovanni.
Bortolussi's conversion attempt was wide of the posts but Ireland had every reason to be worried with the gap down to five.
But nerves were eased a little as O'Gara landed a penalty awarded for a handling offence on the floor.
However, Bortolussi's second penalty brought it back to 16-11 to make things a little too close for comfort for the Triple Crown holders.
Ireland: Dempsey, Trimble, B O'Driscoll (capt), D'Arcy, Murphy, O'Gara, Reddan; Horan, Best, Hayes, O'Callaghan, O'Kelly, Easterby, D Wallace, Leamy.
Replacements: Jackman, Buckley, M O'Driscoll, Heaslip, Stringer, P Wallace, Kearney.
Italy: Bortolussi, Robertson, Canale, Mi Bergamasco, Canavosio, Masi, Travagli; Lo Cicero, Ghiraldini, Castrogiovanni, Dellape, Del Fava, Sole, Ma Bergamasco, Parisse (capt).
Replacements: Festuccia, Perugini, Cittadini, Reato, Zanni, Marcato, Galon.