Josh Sargent scored his fourth goal of the tournament when he deflected in an effort from Justen Glad.
A United States team reduced to 10 men sealed top spot in Group E of the FIFA Under-20 World Cup on Sunday with a 1-1 tie against Saudi Arabia.
Win means they now need a point against Saudi Arabia on Saturday to be certain of a place in the second round.
Early goals from Ibrahima Niane and Cavin Diagne sealed a 2-0 victory for Senegal over Saudi Arabia in their opening 2017 FIFA Under-20 World Cup game
Luca de la Torre scored an injury-time goal to rescue a 3-3 draw for the United States against Ecuador at the Under-20 World Cup.
The U-20 international has signed a three-year deal with the Spanish side.