Lizzie Bohama fed Villarreal a ball which she took down the area and in a triangulation with another striker, put the ball in the back of the net.
Kendall Bodak scored first followed by Charlotte Kohler, both on assists to make the score USA 2, Argentina nil.
The USA took that lead into halftime but then scored twice in a four-minute span early in the second half to put the game away. Once again Boamah started the goal-scoring attack by breaking pressure with a dribble into midfield. Her pass found forward Amalia Villarreal on the backline. Villarreal played a quick combination with Kohler, receiving the through ball back from Kohler inside the penalty area and finishing to the far post with her right foot.
In the 55th minute, midfielder Grace Restovich jumped on a loose ball on top of the six-yard box after a corner and smashed a first-time shot on the half turn into the upper 90 for the final scoreline.
Argentina, which was playing with numerous full National Team players, out-shot the USA 12-5, but the young Americans were clinical in their finishing and goalkeeper Kealey Titmuss earned the shutout while making six saves.
Villarreal will be attending The University of Texas on a full soccer scholarship next fall and is the daughter of Gretchen and Mario Villarreal (of Eagle Pass) and the elder sister of Martina, another up and coming soccer star.