The United States did well to recover from their opening match defeat and beat Cameroon 4-1 in their second game at the 2009 World Youth Championship.
USA went into half time with a 1-0 lead thanks to a 45th-minute goal from Bryan Arguez, and needed only two minutes after the break for Tony Taylor to double the advantage.
Dilly Duka added a third in minute 67, although a penalty goal from Banana Yaya restored the original gap nine minutes later.
The fourth and final American goal came from 19-year-old midfielder Brian Ownby near the full time whistle.
The US are now in second place in Group C, a point behind leaders Germany.