Some days, winning is no more than a matter of dropping the net into the water and seeing what you haul out. Ireland didn't take a bounty into the boat in Croke Park yesterday but they got enough for a 29-11 victory over Italy in their first Six Nations match of the year and came away glad that it was all that was needed. There'll be stiffer tests between now and 20 March and indeed for long stretches here, you sensed that a grouchier opponent might have shaken Ireland from their torpor.

As it was, they hit the front early and idled when they got there – not the best habit to be forming at this stage.

But a win is a win, sufficient onto the day and all that. There's plenty of rust to scrape off before the bandwagon can be declared roadworthy, a point not lost on Declan Kidney. "There's loads we want to work on and get better," he said. "We needed a few more passes to stick. Last year we won by a distance because we got two intercept tries. Italy defended in a different way today and we didn't get any."

In the land of well-he-would-say-that, Kidney is the long-crowned king. While this ultimately ended up being an unsatisfying hotchpotch of a day, the truth is that for long stretches of the opening half Ireland rocked and rolled as Italy made you wonder if the right squad got off the plane. The usual ferocity was missing and three times in the first 20 minutes Irish players took a stab at chipping over them to keep them turning. And when they weren't craning their necks, they were waving at runners as they glided by.

Andrew Trimble made hay early on and it was his break from a zipped Ronan O'Gara pass after 15 minutes that set up the first try. He ran 30 yards, set up the ruck and a few phases later Jamie Heaslip cut onto a David Wallace pass under the Cusack Stand to knife the tournament's first five-pointer. Tomás O'Leary crafted a cheeky second shortly after the half hour, calling Cian Healy over at a ruck and then diving for line himself as the Italian defence got distracted. Schoolboy stuff that got a schoolboy grin from the Munster scrum-half as he walked back to halfway.

It was all rather a lark by now. Italy carried all the menace of a cheerleading troupe and Ireland treated them accordingly. It seemed that every half-move they pulled came off and every mini-break gained yardage. O'Gara kept the car running with six kicks from six and when Argo-Italian centre Gonzalo Garcia got a spell in the bin for a spear tackle on Brian O'Driscoll, it looked a mere matter of popping the sail and coasting to the shore.

Thing is, that's alright for the rest of us to assume as we stretch and yawn in the stands but complacency has consequences between the lines. Not two minutes after O'Leary's try, a speculative punt down into the Ireland 22 hopped up for Rob Kearney and when he chose to clear with all the urgency of a young dad out having a kickabout with his boy on a Sunday afternoon, Kaine Robertson blocked him down and got to the rebound first.

From nowhere, Italy had a try on the board. And when they scored the first points of the second half to bring the score to 23-11, it applied a full stop to the afternoon's fun. Ireland were never in any trouble – O'Gara flicked over a penalty immediately from the restart just in case anyone was getting notions – but from there until the end, it felt like party after the neighbours had asked if the music could be turned down. The crowd got what they came for but nobody got their rocks off.

"We had a very tough second half where we got no continuity," said O'Driscoll. "But there's no point producing your best today and going downhill. We'd want the slope going in the other direction."

All that was left was a little injury housekeeping – O'Gara (leg), Trimble (hamstring) and Paul O'Connell (eye) are expected to be dressed and ready for training tomorrow. Small tussle in Dublin, not many hurt.

The same performance won't do much damage in Paris next Saturday. But then, they hardly need us to tell them that.