Left-hander Tucker Davidson, remembered from Triple-A Gwinnett because of his second start this season, gave up one hit 5 2/3 innings with five walks and five strikeouts.
Swanson extended his hitting streak to a career-best 12 games. He's five homers in that stretch, including in back-to-back matches against Washington. The homer landed about halfway up the left-field seats, his 10th this year.
Atlanta had just two hits off Corbin (3-5) in five scoreless innings before discovering success against the left-hander from the sixth.
Ronald Acuña Jr. started the inning with a single, stole second and scored on Ozzie Albies' only that skipped past left fielder Josh Harrison for an error. Austin Riley drove Albies from second base with a double down the right-field line.
Corbin allowed four runs, six hits and two walks in 5 1/3 innings, leaving his ERA in 6.28.
Albies drove in 2 runs with three hits, including a double off Sam Clay in the seventh. The shot off the right-field wall drove Acuña, who walked.
Josh Tomlin (3-0) threw 1 1/3 scoreless innings after substituting Davidson in the sixth. With two outs in the ninth, Jordy Mercer doubled off May Smith and scored on Alex Avila's single up the middle.
Davidson escaped difficulty in the fifth, when Victor Robles headed off with a walk and moved into second on Jordy Mercer's single to right field for the Nationals' first hit. Davidson recovered by striking out Alex Avila and Corbin before Trea Turner's groundout ended the inning.
Swanson's homer and Albies' double gave every infielder 500 career strikes.
Riley delivered the defensive play of the game in the first time when he made a diving stop of Ryan Zimmerman's grounder near third base. Riley threw from his knees Ozzie Albies at second base to push Harrison.
He left Wednesday night's match after his knee locked when diving for a ball. Manager Dave Martinez stated Schwarber was accessible just to pinch hit and said"we only want to be cautious. ... He said it was a little tender."
Braves: IF Johan Camargo has been optioned to Triple-A Gwinnett to clear a roster spot for Davidson to be recalled. Camargo has no strikes at 15 at-bats with six strikeouts this year.
Nationals: RHP Max Scherzer (4-4, 2.34) will attempt to keep his success at Philadelphia once Washington opens a string from the Phillies on Friday night. Scherzer is 5-1 and Washington is 7-1 in his eight starts at Citizens Bank Park since joining the Nationals at 2015.