Harper hit a long solo homer and a single, helping the Washington Nationals to an 8-6 victory over the New York Mets on Saturday at Port St. Lucie, Fla.
Andrew Stevenson and Matt Skole also connected for Washington, and Gio Gonzalez struck out one in a scoreless first inning. Joe Nathan, bidding to fill the Nationals' closer spot, gave up one hit in a scoreless third inning.
Mets catcher Kevin Plawecki injured his left leg in a collision at the plate with Washington prospect Rafael Bautista and had to be helped off the field.