SEATTLE — The United States returned home from the FIFA Confederations Cup and used one of its youngest lineups in recent memory to rout Grenada 4-0 last night as it opened the title defense the CONCACAF Gold Cup.

Freddy Adu scored the opening goal in the seventh minute and Stuart Holden doubled the lead in the 31st, both fed by Robbie Rogers.

Rogers scored in the 60th minute and Charlie Davies, one of the few players kept on from the Confederations Cup, got the final goal in the 68th.

The 12th-ranked Americans, seeking their third straight Gold Cup title, the regional championship of North and Central America and the Caribbean, outshot No. 88 Grenada 25-3.

Seven of the U.S. starters entered with a combined 11 international appearances, with goalkeeper Troy Perkins playing just his second match for the national team.

Right back Steve Cherundolo, sidelined with a hip injury for most of the past six months, was the only regular starter in the lineup. He was joined by three frequent national team backups: left back Heath Pearce, and Adu and Davies, who got a key goal against Egypt at the Confederations Cup.

Adu’s goal was just his second for the national team — the other was in a World Cup qualifier against Guatemala last November. Holden, who turns 24 next month, became the first American to score in his international debut since Eddie Robinson against Sweden in January 2008, and Rogers scored his first goal in his second appearance. It was the third goal for Davies.

The U.S., 22-0-1 in group play in the Gold Cup, next plays Honduras on Wednesday in Washington, D.C. The Americans close the first round against Haiti on July 11 at Foxborough, Mass. Honduras opened the Gold Cup by beating Haiti 1-0.