"You just keep battling. Just one game can turn you around and get some momentum going," Johnson said. "Things can change quick. ... They outplayed us, plain and simple. There are a lot of games left. We have a lot of ground to make up. You never know what can happen in this game. If nothing else, [you have pride] by playing better."
Said Jayson Werth: "It's getting to a point where we're just not winning games, and you hate to accept losing at any point, but the losses are definitely piling up."
It was Washington's bullpen that couldn't keep Atlanta from scoring. Right-hander Ryan Mattheus started the eighth inning by retiring the first two batters he faced. Then Andrelton Simmons doubled to left-center field and pinch-hitter Joey Terdoslavich drew a walk to put runners on first and second in a 3-3 game.
"I've got to finish the job," Mattheus said. "I got two more guys to get out, and I just didn't do it. So that one's on me tonight."
Johnson decided to take Mattheus out of the game in favor of left-hander Ian Krol, who had a tough time getting hitters out. Jason Heyward -- a left-handed hitter -- singled to right field, scoring Simmons. Justin Upton followed and doubled to left field, scoring Terdoslavich and Heyward.
"I was throwing my slider -- slurve, curveball-slider -- for strikes today," Krol said. "I had it working. But I was just filling up the zone with my pitches too much and left it over the plate. Obviously, I wanted it down and out of the zone.
"Heyward is a good low-ball hitter, but I was kind of second-guessing myself. I think I should have thrown an inside fastball up and in on him, but it is what it is."
David Carpenter and Craig Kimbrel blanked Washington the rest of the way. The two teams meet again for another three-game series in Atlanta starting Aug. 16.
"This was a big series," Braves first baseman Freddie Freeman said. "We pushed the lead to three more games up on them. We came in here and we let them know we're here to stay. They're going to come back to our place next week and they're going to be looking for payback. We've got to be ready for them."
Nationals starter Jordan Zimmermann lasted four innings and allowed two runs on seven hits. He threw 88 pitches, and Johnson said he left the game because of tightness in his neck. But Zimmermann said, "That's news to me." He said he wasn't shocked that he was taken out of the game. He never had a clean inning.
"Every inning, the leadoff guy seemed like he was on," Zimmermann said. "Like I said, I had good stuff. I just fell behind or let them back in the count when I had them 0-2."
The Braves scored the first run off Zimmermann in the first inning. Heyward led off with a double and came home on a single by Freeman.
Atlanta made it a 2-0 game in the fourth inning. With the bases loaded and no outs, Dan Uggla scored on a sacrifice fly by Kris Medlen.
Medlen had one of his best outings of the season, going seven innings and allowing three runs on three hits. One of those hits was a two-run home run by Werth. Medlen retired the first 10 batters he faced before allowing a walk to Bryce Harper, who scored on the Werth homer.
With Fernando Abad on the mound, Atlanta took a 3-2 lead in the seventh inning, when Upton swung at an 0-1 pitch and blasted it over the left-field wall for his 21st homer.
But the Nationals came back and tied the score in the bottom of the inning. They had runners on first and third with one out when Ian Desmond hit a slower roller to Simmons at shortstop, and he was able to get the forceout at second but the Braves couldn't complete the double play, allowing Werth to score the tying run.
The Nationals dropped their record to 54-60.