"[The 0-1 changeup] just kind of faded too much towards the middle of the plate, and he put a pretty good swing on it. That's what good hitters do," Gilmartin said of Harper's homer.
The Mets also had an injury scare during the sixth inning when Nationals outfielder Rafael Bautista slid headfirst into the plate and collided with catcher Kevin Plawecki, who fell to the ground in pain. He was removed from the game with an left knee contusion and was replaced by catcher Xorge Carrillo.
Both teams had played a group of their regular position players on Saturday.