The all-action forward entered the fray for Nicolas Gaitan on 67 minutes with his side 3-0 up in the Gillette Stadium in Foxborough.
West Brom's Salomon Rondon pulled a goal back on 70 minutes but two minutes later, Erik fired low past Dani Hernandez. It was his second goal in the tournament after scoring against Bolivia in Argentina's final group game.
Lionel Messi earlier equalled Argentina's goalscoring record with his 54th goal and Gonzalo Higuain struck twice.
The win means Argentina will now play hosts America in the semi-final at the NRG Stadium in Houston on Tuesday. DeAndre will be available again after missing USA's quarter-final win against Ecuador through suspension.
Below: Erik celebrates his goal with Lionel Messi