Ireland suffered an agonising 2-1 defeat in the semi-final of the Electric Ireland FIH Champions Challenge I at UCD.
With the scores level, Lauren Pfeiffer converted America's tenth penalty corner and pushed into the lead for the first time in the 58th minute.
The victors will now face Australia in Sunday'’s final at 4.30pm, while Ireland will play for the bronze medal against Scotland at 2pm.
Ireland opened the last-four clash with a dream start and goal in the third minute when Lisa Jacob deflected in at the right post from O ‘Flynn’s drag flick. But in a fast paced, exciting game it wasn’t long until the USA got a great chance to equalise in the 11th minute with a penalty corner chance but O'Donnell just missed the touch in.
The Irish had to mop up pressure in the form of five further USA penalty corners but a solid looking Gray in goals flanked by a strong defence denied the States set piece routines.
The home side had a superb chance after the fifth US penalty corner with a fast paced counter but Crowley on the ball just couldn't get the angle and her effort was met with the side net and Ireland closed out the half with their 1-0 intact.
The USA came out all guns blazing and made their presence felt in the 37th minute when they equalised thanks to Kathleen O’Donnell’s goal from open play.
Gray in goals was back in action three minutes later smothering an effort from Taylor to keep all things square. Ireland were back in attacking mode just four minutes later when O'Flanagan secured Ireland another penalty corner but the ensuing attack led to a free out for obstruction by the girls in green.
Ireland continued to make chances with some great interlinking play down the right, Connery, Watkins and Smyth showing some great flair but the finishing touch evaded the girls.
The visitors continued to secure penalty corners and Gray in goals showed fine form in keeping the set pieces out. But eventually got their noses in front thanks to Pfeiffer
With time running out Ireland dug deep looking to equalise including a penalty corner opportunity in the 65th minute but with the injection misplaced the set piece went off plan and McCarthy's strike was defended and cleared and the game closed out 2-1 to the USA.
Commenting after the game, Ireland coach Dennis Pritchard said: "When we played well, it was an even game, however at crucial times their experienced players controlled the midfield areas.
"We needed to get back into contention but failed to maintain possession for long enough spells to do so, at times we were too technically loose."