Andrew McCutchen continued his torrid run against the Nationals with three more hits and A.J. Burnett spun seven innings of one-run ball in Pittsburgh's 3-1 victory over Washington.
McCutchen hit his 11th career home run against Washington, and has gone an impressive 41-for-90 in 24 career games versus the club. Jordy Mercer contributed a two-run homer to help the Pirates to their second straight win.
Burnett (3-2), unbeaten in his last five starts, struck out nine and allowed just five hits. Jason Grilli worked around a one-out single in the ninth to notch his 12th save of the season.
Washington fell for the fourth time in six games, with Ross Detwiler (1-3) suffering a third straight losing decision. The lefty gave up three runs on six hits and two walks over five-plus frames.
Adam LaRoche went 2-for-3 and Danny Espinosa plated the Nats' only run with an RBI single in the setback.
The Pirates struck first, with McCutchen's two-out solo blast to left staking the hosts to a 1-0 lead.
Burnett's only trouble came in the fourth, when the Nationals were able to draw even, but struck out four and gave up just one hit over his final three innings of work.
"We're fine, we're right where we need to be," said Nationals shortstop Ian Desmond. "He pitched good, don't take any credit away from him, he pitched a really good game today."
LaRoche sparked a two-out rally in the fourth with a walk, moved to second on a base hit from Tyler Moore and scurried home on Espinosa's ground ball into right. The inning came to a close on Espinosa's hit, however, as Moore was thrown out trying to advance to third.
Pittsburgh then went in front for good in the fifth. Mercer, recalled from Triple-A Indianapolis earlier on Friday, pulled a pitched from Detwiler that just cleared the left-field wall for a two-run homer, making it 3-1.
"I got myself in a good count and just let it fly," said Mercer. "Anything I can do to help the team win, and it was a good win."
Before going down in the ninth, the Nationals had a chance in the eighth with runners on first and third for Bryce Harper, who was picked off first base back in the sixth inning.
Harper would go down swinging to end the frame and finished just 1-for-4 on the night.
The Pirates made several moves earlier on Friday, placing infielder Neil Walker on the 15-day DL (retroactive to April 27) with a right hand laceration. They also selected the contract of pitcher Jose Contreras from Triple-A Indianapolis and optioned pitcher Jared Hughes to Indianapolis ... Pittsburgh right fielder Brandon Inge had an eight-game hitting streak snapped ... Washington's Ryan Zimmerman was activated off the disabled list and played for the first time since April 21. He went 0-for-4 with four strikeouts ... Washington infielder Anthony Rendon was optioned to Double-A Harrisburg ... Desmond went 1-for-4 to extend his hit streak to nine games.