Eddie O'Sullivan was left to pick the bones of a far from convincing performance compounded by the possible loss of his captain, Brian O'Driscoll, for the match against France on Sunday.
The naturally cautious coach was clearly relieved after his side had been put through the mill by an under-strength Wales. He said: "We got away with that one. It was far from a vintage performance and we made a lot of mistakes.
"That's not normally the road map for getting out of Cardiff with a win. But we won the game three tries to nil so there's obviously something positive. If we play like that against France next weekend, we're going to be in trouble."
Having created the first and scored the second of his team's three tries, O'Driscoll hobbled off five minutes from time with a hamstring injury. O'Sullivan said: "The worry was that he could have caused more damage and been out for the Championship had he played on, but he has a much better chance because we got him off at the right time."
O'Sullivan admitted his team were stretched by a Welsh side who had a strong call for a penalty try waved away when Simon Easterby barrelled Chris Czekaj over yards from the line.
O'Sullivan said: "There were times when the game could have changed had Wales scored but that's the rough and tumble of Test rugby. Psychologically the game ebbed and flowed but when the chips were down in the final 20 minutes, we dug in and closed out the game. Experience was a big part of this win. We didn't panic and we were very composed under pressure."
His opposite number, Gareth Jenkins,said: "It was a missed opportunity. We played all the rugby but did everything apart from score tries.
"Ireland are a wise old bunch and controlled the game without the ball for long periods. Our endeavour, style and intensity was great but perhaps we're still a little naïve and we have to learn these lessons fast before going to Scotland."
Asked about the New Zealand referee, Kelvin Deaker, Jenkins said: "You have two teams trying to stop each other playing and the guy in the middle has a big responsibility. The contact area is key; if you don't referee the area particularly strongly you can end up taking the game away. That was a frustration for us."