Defender Emily Fox scored her first international goal while midfielder Lindsey Horan added another off a converted penalty to earn the win in front of an electric sellout crowd of 20,593 fans at Q2 Stadium.
It was a physical match from the jump and the early part of the game was a chess match with both teams alternating in possession and most of the play taking place in the middle third as the USA tried to find ways to break the Irish down.
The USA posed its first threat in the eighth minute after a good run of controlled possession resulted in a cross by defender Crystal Dunn from the left side that met forward Sophia Smith inside the box. Smith, who made her first appearance of the year after recovering from a minor injury, stretched to connect with a shot but her attempt went just wide.
Ireland came close to opening the scoring in the 19th minute after a corner kick led to a header at the back post, but forward Alex Morgan did well to deny the danger off the goal line and midfielder Rose Lavelle followed up with a clearance. Five minutes later, Ireland strung together a series of consecutive attacks that saw the USA put its defensive quality on display as the team denied several consecutive shots from close range.