After losing their opener 2-0 to Colombia, the United States were in clinical form against the Central Americans and scored three times in the first half through Clint Dempsey, Jermaine Jones and Bobby Wood.
Substitute Graham Zusi added a fourth in the 86th minute to cap the win and improve the hosts’ goal difference.
“It was important for us to get off to an early start,” said Dempsey. “Once the second went in and the third we got into a bit of a rhythm.”
Dempsey got the first, his 50th international goal, from the penalty spot after Cristian Gamboa was adjudged to have pushed Bobby Wood in the box with six minutes gone.
Dempsey was involved in the Americans’ second after 36 minutes when his run at the Costa Rica defense saw the ball fall to Jones, who struck a low shot from the edge of the box past the outstretched hand of goalkeeper Patrick Pemberton.
The third goal came five minutes later and once again it was Dempsey who set it up. Wood won the ball in midfield and played a one-two with Dempsey before turning to strike home a low drive from 15 yards out.
Costa Rica, who reached the World Cup quarter-finals in 2014, improved in the second half with captain Bryan Ruiz playing a more influential role, but they were ineffective in the last third of the field.
Ruiz hit the post with a header midway through the second half but Costa Rica lost a fourth goal in the dying moments when Zusi stole the ball in midfield and strode forward before slotting the ball home from 15 yards.
The result takes the United States top of Group A, with Colombia currently playing Paraguay in Pasadena.
The United States next meet Paraguay on Saturday, while Costa Rica will need to beat Colombia to have any chance of advancing to the quarter-finals of the 16-team tournament.