Several key moments in the game also included Denard Span, Wilson Ramos, Blake Treinen and others.
The Nationals' starter has begun to bounce back from the most prolonged slump of his career.
After Doug Fister went only two innings, Treinen pitched much longer than he had all season.
Harper had a good reason to get mad but the Nationals needed him to stay in the game.
Robinson fired a scoreless, nine-pitch eighth inning to save the bullpen from throwing more.
Over the past five games, Washington relievers have allowed three runs in 11 1/3 innings, given up four hits and struck out 13.
Ian Desmond made a stellar play at shortstop that could be a sign of his turning defensive play.
The Nationals have steadied themselves against National League East competition, but will face one of the National League's best teams this week.
Mixing and matching early this season has been a challenge.
He leads the team in hitting, two-strike hits and contact.