Harper, who came within inches of hitting for the cycle, led off the eighth with a triple off Cam Bedrosian and scored on Ryan Zimmerman's single to give the Nationals a 3-2 lead. Adam Lind added an insurance run with a solo homer in the ninth, and newly acquired relievers Ryan Madson and Sean Doolittle sealed the victory by pitching the final two innings in their Nationals debuts.
The Angels pulled within one in the ninth after Ben Revere scored on Trout's groundout, but Doolittle coaxed a flyout from Albert Pujols to end the game.