Washington went to work against Braves right-hander Ervin Santana in the first inning by scoring four runs. Denard Span started things off with a double and later scored on a single by LaRoche. Ian Desmond followed and singled to left, which sent Jayson Werth home to make it a 2-0 game.
Two batters later, Wilson Ramos singled to right field, sending LaRoche home, while Asdrubal Cabrera followed with a sacrifice fly to score Desmond.
"They came out swinging the bats and were really, really aggressive with the first couple pitches of every at-bat," Braves manager Fredi Gonzalez said. "Usually, when they do that against [Santana], they get quick outs. But they found the outfield grass and put a big number up -- four runs. We weren't able to recover after that, but we battled."
The next inning, Washington took advantage of an error by Braves catcher Christian Bethancourt. After Werth walked with two outs, Bethancourt tried to pick off Werth at first base. But the rookie threw the ball past first baseman Freddie Freeman, and that allowed Werth to go all the way to third. Werth then scored on a single to right field by LaRoche.
"The thing that I liked about [the offense] was it wasn't by the homer," Nationals manager Matt Williams said. "It was a good approach. It was hitting the ball back through the middle. That's kind of our team. That's a good thing."
LaRoche is the hottest hitter on the Nationals. Since Sept. 3, he is 9-for-19 (.474) with four home runs and 12 RBIs.
"It feels good. I'm slowing things down. I'm going deep in counts. I'm getting some pitches to hit. The whole lineup is looking pretty good," LaRoche said.
The run support would be just enough for right-hander Jordan Zimmermann, who allowed four runs (two earned) in six innings and struck out seven hitters.
Atlanta scored its first two runs in the top of the fourth inning. With runners on first and third and one out, Jason Heyward hit a grounder to LaRoche at first. LaRoche was able to get the force at second, but Desmond threw the ball away while trying to double up Heyward at first. Phil Gosselin scored on the play, while Heyward went to second. Chris Johnson then singled to right field, sending Heyward home.
After the Nationals scored their sixth run of the game on an RBI double by Werth in the fourth, the Braves made it a two-run game when Justin Upton hit a two-run homer off Zimmermann in the sixth. The homer followed a throwing error by Danny Espinosa, who had replaced Desmond at short to begin the inning.
"I felt OK. I didn't have my best stuff. The fastball was like a tick off. I ran into some deep counts," Zimmermann said. "A couple of at-bats by [Emilio] Bonifacio cost me 15 to 20 pitches. That's why I wasn't able to go longer. Overall, I felt OK. It was just a little bit of a battle tonight."
The Nationals had to do without relievers Tyler Clippard and Rafael Soriano on Tuesday. Clippard was just given the day off, while Soraino was working on his mechanics. There were still nine outs to get, however.
That's when Williams decided to match up against certain Braves hitters. It started with Aaron Barrett, who pitched 1 1/3 innings. After allowing a leadoff double to Bonifacio and inducing Gosselin to ground out in the top of the eighth, Williams called for left-hander Ross Detwiler to face Freeman, who struck out on a curveball. Craig Stammen entered the game to face Upton, who struck out to end the threat.
"They came in to get the guys they had to get," Williams said. "The matchups are there. We want to bring Det for Freeman. He threw him a real nice curveball. And then Stammen [pitched against] Justin. [Stammen] threw him a couple of sliders to get ahead. Then bounced a couple and then really made a nice pitch to strike him out."
Drew Storen pitched the ninth and had another dominating performance for the third straight day. He picked up his fourth save of the season. After the game, Williams declined to name Storen his closer, insisting that he will use his bullpen based on matchups.
"He was economical with his pitches again tonight. I wouldn't anticipate he would pitch tomorrow, though," Williams said about Storen. "He really did a nice job during the last three games."
The Nationals improved their record to an NL-best 82-61 and are a season-high nine games ahead of the second-place Braves.