
Zimmerman (13-8, 3.49 ERA) went six innings, giving up two runs on six hits, striking out seven and walking one.
Jonathon Papelbon notched his 24th save despite allowing two hits in the ninth.
Moore hit a solo homer to key a three-run fifth for Washington, and Harper went deep in the seventh with a two-run shot, his 41st of the season.
Washington (77-71) gained a game on the New York Mets, who lost to the New York Yankees, 5-0, on Saturday, and now lead the Nats by seven games with 16 to play.