The World Champions won the tie 3-0 after piling the pressure on the Irish team, determined to kick-off their victory tour with a bang in front of 37,040 people at the Rose Bowl Stadium in Pasadena.
Tobin Heath, who came into the USA starting line-up at the last minute after Mallory Pugh pulled a muscle in the warm-up, got the opener with 16 minutes on the clock.
Some excellent Irish defending and top-drawer saves from Irish goalkeeper Marie Hourihan managed to keep the USA onslaught at bay for a period until the 31st minute when Lindsey Horan doubled their lead.
And it was 37-year-old, 281 time-capped USA hero Carli Lloyd who made it three for the home side 10 minutes later on 41’.
But there were positive glimpses for the Irish women in the first 45 - Amber Barrett came close to levelling the game on 22’, but she curled her shot wide.
After regrouping at the break, Ireland came out fighting and despite the USA introducing household names such as Rose Lavelle and Ali Krieger, the world champions could not add to their tally.
Ireland interim manager Tom O’Connor explained that while he never likes to lose a game, he was delighted with the determination shown by his side.
“It’s 3-0 and no one likes to lose, but I think you have to put it in context. We’re playing against the world champions in their home match, on their victory tour. Overall, I’m very, very pleased with the performance and the way the girls played tonight,” said O’Connor.
With the USA looking clinical in the first 45, it was the way his team approached the second-half that really pleased O’Connor.
He said: “It was a tough first half, we didn’t see a lot of the ball. But the second half was a different story. After the first 45 minutes and with them three up already, we knew we had to get the shape right and overall I’m delighted with the second half performance.”
And with the opening game of the European Championships against Montenegro on September 3 just under one month away, the interim manager feels the future is bright for the young team.
He said: “To bring a 17-year-old, Eabha O’Mahony, on and for her to do so well was great. We had a few players making their debut or getting their first starts and they did very well, so that bodes well for the team for the future. Niamh Farrelly and Jess Gargan were excellent, they didn’t look out of sync at all. With all that in mind, we’ll look forward to the start of another campaign.”
Republic of Ireland: Marie Hourihan, Claire O'Riordan, Louise Quinn (Claire Walsh), Diane Caldwell, Jess Gargan, Harriet Scott, Niamh Fahey, Niamh Farrelly, Amber Barrett (Rianna Jarrett), Heather Payne (Eabha O’Mahony), Katie McCabe.
USA: Alyssa Naeher (Ashlyn Harris), Tobin Heath (Jessica McDonald), Carli Lloyd (Ali Krieger), Christen Press (Rose Lavelle), Lindsey Horan, Julie Ertz, Sam Mewis (Allie Long), Crystal Dunn, Becky Sauerbrunn, Abby Dahlekemper, Kelley O’Hara (Emily Sonnett).
Referee: Ekaterina Koroleva (USA).