An Ireland side made up entirely of Magners League players never looked in danger of being on the wrong end of a substantial upset in the tournament's opening game.

First-half tries from Leinster's Jamie Heaslip and Munster's Tomas O'Leary, together with 16 points from the boot of Ronan O'Gara and a penalty from Paddy Wallace were enough to see off a disappointing Italian outfit by 29 points to 11.

In truth, the win masked a lacklustre performance by Declan Kidney's men who never really reached the heady heights of a memorable 2009.

Having secured a first European clean sweep since 1948 and gone an entire calendar year unbeaten, Irish expectations were unsurprisingly high going into the start of the Six Nations.

But Ireland never kicked into gear in their penultimate European fixture at Croke Park as Italy almost succeeded in bringing the reigning champs down to their level in a frustrating encounter.

Ireland looked set to take a 20-point lead into the half-time break after a fine run from returning Ulster wing Andrew Trimble eventually set up Heaslip in the 16th minute and a well-taken lineout steal from Leinster skipper Leo Cullen allowed O'Leary to snipe over from close range a quarter of an hour later.

But a mistake from Rob Kearney gifted Kane Robertson an undeserved score just before the break after the Lions full back saw his attempted clearance charged down by the Italian wing deep inside the Ireland 22.

A disappointing end to the first half seemed to set the tone for the second, as neither side produced their best in the final 40 minutes.

A penalty a piece from O'Gara and Wallace compared to a single Mirco Bergamasco effort proved the only points of the half as Italy dug deep to prevent Ireland from running up the kind of heavy score that many pundits had predicted.

But while Ireland's overall performance may have been below par, the result sees them move on to Round 2 with a decent chance of becoming only the fifth side to win back-to-back Grand Slams.

They travel to Paris next weekend knowing an improved showing will be required to keep that goal alive, but recent results suggest that this Ireland side are more than capable of stretching their unbeaten run even further at the Stade de France.