Harper went 3-for-5 with a double and a run scored in Wednesday's 5-2 extra-inning win over the Nationals.
The 28-year-old continued to torment his former club, going 4-for-8 over the first two games of this series. On the season, Harper is hitting .308 through 29 games with seven homers, three steals, 11 RBI and 24 runs.