PITTSBURGH (AP) — Bryce Harper belted his 13th home run, Ryan Zimmerman smacked a two-run double to add to his major league-leading RBI total and the Washington Nationals held off the struggling Pittsburgh Pirates 8-4 on Tuesday night.

Harper’s laser to the last row of seats in right field in the ninth gave the 24-year-old star a home run in every ballpark in the National League. He finished with two hits to move ahead of Zimmerman for the major league-lead in batting average (.388).

Zimmerman had two hits, including a double in third inning that gave him 38 RBIs on the season. Jayson Werth added three hits and is batting .457 (16 for 35) in his last nine games.

Stephen Strasburg (4-1) allowed three runs in six-plus innings, walking one and striking out three on a night he didn’t have his best stuff.

Josh Harrison had two hits for the Pirates, including his sixth home run of the season, and also avoided a tag at second base with an acrobatic slide in the sixth. Chad Kuhl (1-4) remained winless since the first week of the season.