The wind and rain made for difficult handling and place-kicking conditions, and it took a fiery five-minute spell around the hour mark to break the Americans' resistance.
Tries from Rory Best and Tommy Bowe extended the margin to 17 points in what was a much more cohesive second half display from the Irish.
The scrum, lineout and defence were areas of encouragement for the management to reflect on, as were the high standards set by the likes of Best, Paul O'Connell and Stephen Ferris.
Accepting that opening night nerves contributed to some of the mistakes, head coach Declan Kidney said: "The first game of the Rugby World Cup is like the first game of the Heineken Cup multiplied by 20.
"It's unbelievable how nervous everybody gets in the build-up to it. It's not from a lack of effort, if we had a poor attitude out there I would say so, but I think our attitude was probably we were just too uptight and we have to learn to relax and let our ability take over.
"The fellas out there are good players and you know that's not the norm for them. All the areas are things that are within our control and once they are within your control then you have something to work with."
The 22-10 win made it four Rugby World Cups on the trot that Ireland have been victorious in their opening match. However, certain aspects of Ireland's play, particularly the attack, will have been improved upon as Tri Nations champions Australia are next up in Auckland.
Kidney added: "Australia is a whole different kettle of fish. What we had to do to beat America was one thing, we just have to be smart when we play Australia next week. That's what we have to do.
"You always want to have things free-flowing going into it but it is what it is, we just need to work on it.
"Sometimes just by calming down a bit and we need every day in training between now and then to get it right, we need to take a look at it, but you know you have good players and you work with them."
"Because it is each individual's responsibility to mind the ball and there were one or two balls kicked down to us, where we conceded field position. Yeah, individual responsibility."
Things might have been a lot smoother had Ireland taken most of their scoring chances. Jonathan Sexton struggled with his place-kicking, missing four of his six shots at the posts, while Keith Earls went close to sniffing out a try and some late lineout mauls and scrums should have translated into further scores.
"That is what the lads are frustrated with. Had we been ticking the scoreboard better than we had been doing then everybody relaxes a bit, a few more passes go to hand and all of a sudden you run in a few (tries).
"You saw Scotland once they got the lead, they relaxed and got another try, France against Japan, we didn't quite do that in the last 10 minutes."
Cian Healy, Sean O'Brien and Rob Kearney will come into contention for the showdown with the Wallabies, having missed out on the opening game.
Tony Buckley, the tenth Irish player to make his World Cup bow in New Plymouth, took a bang to his shoulder but the rest of the matchday squad emerged unscathed save for the usual bumps and bruises.
Reviewing the team's performance, captain Brian O'Driscoll highlighted the obvious importance of putting the first win on the board. Less we forget that England struggled to put the USA away in their opening game of the 2007 World Cup and ended up reaching the final.
"There were aspects that were disappointing, but the most important thing was that we broke our losing sequence and won the game," said the 114-times capped centre.
"You have to win games ugly if necessary. This win might not have been a thing of beauty but we got across the line and that's the most important thing.
"We're sitting on four points when at the start of the day we had nothing. It's something to work on. Now comes a huge challenge - playing Australia."
Follow the Ireland team in New Zealand on www.twitter.com/irfurugby.