Nationals 2, Braves 0: Stephen Strasburg and two relievers combined on a six-hit shutout and Jesus Flores hit a solo home run to help host Washington preserve its National League East lead.
Washington entered the day with a one-game lead over Miami and the New York Mets in the division and increased its lead over Atlanta to three games.
Flores hit his second homer of the season to left-center in the fifth against Braves starter Brandon Beachy (5-4).
The Nationals added an insurance run in the seventh on Xavier Nady's RBI double off Jonny Venters, but they didn't need it.
Strasburg (6-1) struck out nine over seven innings, allowing just four hits. He did not issue a walk in winning his third straight start, two of which have been against the Braves.
Sean Burnett worked around two hits in a scoreless eighth, and Tyler Clippard worked a perfect ninth for his fourth save.
Beachy allowed two runs on three hits and four walks in 6 1/3 innings to lose his third straight start.
GAME NOTEBOOK: The Nationals have held their opponents to two runs or fewer 23 times this season. … Braves C Brian McCann left the game after being crossed up and taking a pitch off the knee in the seventh inning. … Braves SS Andrelton Simmons made his major-league debut and went 0-for-3 batting in the No. 7 spot. … Nationals OF Michael Morse went 0-for-4 in his season debut.