Ryan Zimmerman had the second of the Nationals’ two grand slams in a 14-4 shellacking of the Braves on Wednesday, but his home run Thursday was more damaging for the home team, driving in the tying and go-ahead runs.

Zimmerman’s two-run homer off R.A. Dickey in the sixth inning lifted Washington to a 3-2 win, completing a three-game sweep before an announced crowd of 27,498 at SunTrust Park. It also continued the Nationals’ domination of the Braves and Stephen Strasburg’s recent success against a team that gave him fits early in his career.

“Dickey did a good job, he just made one mistake,” Braves second baseman Brandon Phillips, who had two of the Braves’ seven hits and scored after a fourth-inning double. “They got key hits early in the game to get the lead. But when he threw that knuckleball to Zimmerman, he knows he wishes he got that back. I think we played a good game. We hit the ball hard, we just hit it right at people and they made some great plays. All you can do is just really tip your hat to them.”

Strasburg (2-0) allowed six hits, two runs and two walks and piled up 10 strikeouts in seven innings, moving to 6-1 with a 2.33 ERA in his past eight starts against the Braves. He’s won four consecutive starts in Atlanta.

The Braves had two on with two out in the ninth against right-hander Shawn Kelly before Ender Inciarte flied out to end the game. The Nationals improved to a staggering 32-9 against the Braves since the beginning of the 2015 season including 18-4 over the past two seasons.

“Your margin of error is really small when you’re facing Scherzer, when you’re facing Strasburg, when you’re facing other great pitchers in our division,” Dickey said. “So it hurts a little bit more when you’re that close to keeping them where you want to keep them and you let one get away from you like that.”

Before the Nats swept through SunTrust, the Braves were riding a five-game winning streak and had a 4-0 home record at their new ballpark following a sweep of the Padres. The Braves start a three-city, nine-game trip Friday night at Philadelphia, where they need to takes a series against the other team at the bottom of the division standings.

Dickey (1-2) was in a groove and protecting a 2-1 lead until a two-out walk to Bryce Harper in the sixth inning, followed two pitches later by the Zimmerman homer to straightaway center on a knuckleball that didn’t move and came in waist-high and over the middle.

In Dickey’s view, the pitch that might’ve changed everything was a 3-1 knuckleball to Harper that looked like it went over the edge of the plate but was called a ball by home-plate umpire Fieldin Culbreth. Harper hit two homers off Julio Teheran on Wednesday including a grand slam.

“I was up there with two outs thinking, keep making quality knuckleball pitches, don’t let this guy beat you,” Dickey said. “And I felt like I did that with him, and (Culbreth) balled a 3-1 that probably would have changed the at-bat that Harper had, because it would have put him in a little more of swing mode, I think. Of course, the next batter, I’ve got to flush that and still execute my pitches, and that’s the part I have to own. But you hope to get calls like that (pitch to Harper) in big situations, and we just didn’t.”

Dickey allowed three hits, three runs and two walks with three strikeouts in seven innings and threw 55 strikes in just 73 pitches. Braves manager Brian Snitker decided to pinch-hit for him after Kurt Suzuki’s leadoff single in the seventh inning, whereupon Emilio Bonifacio struck out to make him 0-for-9 as a pinch-hitter.

Snitker said that if he had the decision to make 10 times, he probably would’ve let Dickey stay in the game five times. Dickey drove in a tying run with a second-inning, bases-loaded ground out and had a two-run single April 8 at Pittsburgh in his Braves debut.

“You can go either way,” Snitker said of the decision. “Thinking offensively right there, Boni can put one in the gap or hit one in the hole and go first and third, have a big inning.”

Dickey said he felt like he could’ve pitched all night, but understood the decision. “I was hoping that I could go up there and bunt. Boni is traditionally a very good bunter; I’ve been playing with him for years, and I completely got (the reasoning for the move). That’s what should have happened, you want a hitter up there in that situation, we need a run.”

Dickey retired 14 of 15 batters between an Anthony Rendon walk in the second inning and the Harper walk in the sixth before Zimmerman’s homer.

Zimmerman also led off the second inning with a double and scored on Michael Taylor’s sacrifice fly to give Washington a 1-0 lead. The Braves answered with a tying run in the second but had a chance to do much more damage after loading the bases with none out. Kurt Suzuki struck out before Dickey grounded to short to bring in a run.

Inciarte followed with a sinking liner to right field that looked like it might drop in for a hit before Harper raced in and snared it with his glove inches above the ground for the third out of the inning. Harper, the player that Braves fans love to hate more than any other these days, had done it to them again.

Suzuki had another chance when he came to bat with the score tied and runners on the corners with one out in the fourth, after a Phillips double and Jace Peterson infield hit. This time, Suzuki’s sacrifice fly gave Atlanta a 2-1 lead.

But two innings later the Nationals used another long ball to reclaim a lead they wouldn’t relinquish again.

Ryan Zimmerman's 2-run homer was the difference for the Nats and Stephen Strasburg, who continued their recent domination of the Braves and swept the second series at SunTrust Park. (Video by David O'Brien)