The Nationals' season-high eighth consecutive victory put them 28 games above .500 and maintained their 4 1/2-game lead in the National League East. They can now play .500 baseball the rest of the season -- going 24-24 in their last 48 games -- and finish the year with 95 wins.
"I'm very aware of that. Not that I expect that to happen, but it's kind of a mathematical equation," Johnson said. "We don't need anybody keeping us honest."
Edwin Jackson struggled early on, allowing four runs over the first three innings, but settled down after that. He walked Stephen Drew in the fourth but got through the inning facing three batters when Jesus Flores caught Drew trying to steal second.
Jackson then set down the heart of Arizona's lineup in order, striking out Paul Goldschmidt and Justin Upton. Given the way Jackson's night started, this kind of game might have been a loss for the Nationals earlier this season. But with this lineup, deeper from top to bottom with the return of Jayson Werth and Michael Morse and big seasons from everyone else, it was a temporary setback.
"Right now, we can afford to have a game like today, when you have a starter out there having to kind of grind through it without his best stuff and still come away with a win," first baseman Adam LaRoche said. "That's nice now, to be able to take a little bit of pressure off of them and allow for some outings like that. It's a huge help.
"When you've got everything going, this is what you get."
Danny Espinosa scored on a Ryan Zimmerman double in the first inning after Upton booted the ball in right field, but the Nationals were then shut down until the fifth, when they finally broke through against D-backs lefty Wade Miley.
"It's very frustrating," Miley said. "It got ugly. ... A team like that, they hit fastballs. You can't throw them down the middle and expect to get away with it."
Steve Lombardozzi reached on a bunt single and took second on a sacrifice bunt by Jackson. Werth drove in Lombardozzi with a double to right. Espinosa reached on a two-base error by Chris Johnson at third base, pushing Werth to third. Zimmerman drove in both with a single to left field, advanced on a wild pitch and moved to third when Miguel Montero's throw to second sailed into center field.
Morse lined a double to center field, scoring Zimmerman, and came around on a two-out single by Flores. The inning finally ended when Lombardozzi, batting for the second time in the frame, popped out to third.
That inning gave the Nats a two-run advantage, but Arizona cut it down to one in the sixth on Ryan Wheeler's pinch-hit RBI double. Tom Gorzelanny entered with the tying run on second and the top of Arizona's order due up but caught Drew looking to get out of the inning.
Washington put the tying run on second base in the seventh and eighth, too, but Gorzelanny, Ryan Mattheus, Michael Gonzalez and Tyler Clippard escaped without allowing a run the rest of the way.
Gorzelanny gave up a leadoff double then struck out Jason Kubel before giving way to Mattheus, who induced two quick groundouts to get out of the seventh. Gonzalez, pitching the eighth because Sean Burnett had the day off, walked two of the first three batters he faced but escaped unscathed. On came Clippard, who worked a 1-2-3 ninth for his 24th save.
"The confidence in the bullpen is at an all-time high," Mattheus said.
"It's a calm confidence," added Clippard. "Nobody gets too high or too low. Nothing changes. We're not walking around like, 'Oh, we're the best.' We're just keeping our heads down and going about our business, playing each game like it's a must-win game. It's a lot of fun, man."
It's also helped them keep the Braves at bay. Atlanta has lost four games since July 23, but Washington hasn't lost any ground in the NL East standings. The Nationals have found ways to win, as they did Saturday night, and continued their push toward the playoffs.
"It's more than the winning streak," Flores said. "A lot of things are going on right now, the chemistry and the guys are very communicating with each other, helping out each other and rooting for each other. They're all doing a great job. ... We're having a good moment, and we have to keep it up."