The Americans are now undefeated, heading into the quarterfinals to be played in Port Moresby on Thursday.
It was a scoreless second half of football in front of 3,076 spectators at the Sir John Guise Stadium this afternoon.
USA midfielder Katie Cousin was awarded the player of the match after another strong performance.
The first goal of the match was scored within 20 minutes by Ghana striker Ernestina Abambila.
The striker hit a highball from the 18 metre out, which US keeper Cassey Murphy fumbled, resulting in a shock goal.