Freedie Freeman and Evan Gattis have a muted celebration after scoring during the Braves’ two-run fourth inning. (Alex Brandon/Associated Press)

Chests out and in first place, with their hottest pitcher on the hill, the Washington Nationals welcomed the team that had bullied them for two seasons. The Atlanta Braves limped into Nationals Park slumping and wounded, with their left fielder on the bench with dizzy spells. Given ideal circumstances to punch back Thursday night, the Nationals managed three miserable hits.

If the Nationals could not beat the Braves on Thursday, when Justin Upton sat, Jordan Zimmermann pitched and Atlanta starter Gavin Floyd exited early with a broken arm, then when will they? The Nationals needed to stomach that question along with a 3-0 loss, which sliced their lead in the National League East to a half-game. The Nationals have three more chances against the Braves this weekend. Their first meeting further established the Braves’ eminence in a division they do not currently lead.

The Nationals are 1-6 against the Braves this season and 7-19 since the start of 2013. Rival evaluators believe the Nationals possess a team with enough talent to run away with the East. But the Braves have still owned them. Before Thursday, the Nationals had won 12 of their past 18 games and the Braves had lost 10 of 15. Once the clock hit 7:05 p.m., none of it mattered.

“I don’t know what it is,” first baseman Adam LaRoche said. “You got to think, losing that many games, it’s not all coincidence. They play us tough, plain and simple. I don’t what it is. Between them and St. Louis, we’re just kind of snake-bit.”

The loss raised another question: Does the Nationals failure against the Braves suggest faulty execution or the need for an altered game plan? The Nationals said they could dismiss the notion of a mental block.

“I don’t think anything is psychological,” Ryan Zimmerman said. “They’re winning games. Just like two years ago and they couldn’t beat us. It’s something that happens in baseball.”

Manager Matt Williams said he saw no need for significant adjustment. He thinks the Nationals need to look inward, to focus on their strengths and perform them well.

“It was just a good performance by their pitching tonight,” Williams said. “They got us tonight, and we’re going to do it again tomorrow. . . . If we execute and we do things properly, we’ve got a chance to win every day, regardless of who we play.”

LaRoche agreed that the Nationals need to play better against the Braves — Thursday night, Jayson Werth doubled with no outs in the seventh and never even reached third base.

“When we do have opportunities, we need to execute,” LaRoche said. “When we get pitches to hit, we need to not miss them. Defensively, it seems like when we play these guys, they find a way to find holes. ”

Zimmermann had allowed one run in 26 innings in three June starts, but the Braves mustered two runs off him with four consecutive singles in the fourth inning. In his ninth start back from Tommy John surgery, Severna Park’s Floyd dominated the Nationals for six innings before he broke his olecranon, a small bone at the tip of his right elbow. The Braves bullpen handled the final three innings by facing 11 batters, polished off by fire-breathing Craig Kimbrel.

Floyd bulldozed the Nationals for six innings, holding them to two hits with one walk and six strikeouts. The Nationals could not resist swinging at Floyd’s breaking ball, a curve that broke wickedly across the plate, often out of the zone. Floyd twirled the pitch 19 times in total. The Nationals swung at and missed eight of them.

“It’s hard,” Zimmerman said. “You don’t really see big league hitters, especially guys in our lineup, swing at pitches like that. But when a guy has a good pitch going, that’s what it does.”

Floyd walked to the mound in the seventh having thrown 63 pitches, only nine outs away from a complete game. He threw Werth a first-pitch curveball, and Werth hammered it out of play to left — the only curve the Nationals made contact with all night.

On the mound, Floyd shook his right arm. A Braves trainer trudged to the mound, and after flexing his arm, the trainer escorted him away. Floyd walked into the dugout with a nauseating sac of fluid protruding from his right elbow. Later, he learned about the broken bone.

Reliever Anthony Varvaro replaced him, and Werth doubled. LaRoche, Zimmerman and Ian Desmond whacked three straight balls to shortstop Andrelton Simmons, a death sentence for grounders.

Zimmermann allowed one base runner in the first three innings, and that came only when Zimmerman misjudged Jason Heyward’s bloop into shallow left field and let it fall for a single. Zimmermann steamrolled once through the Braves’ lineup in 38 pitches.

But the Braves only saw a pitcher wearing a Nationals uniform. With one out in the second, Freddie Freeman, Evan Gattis and Jason Heyward hit consecutive singles. Zimmermann fell behind Chris Johnson, 3-1, with three consecutive balls. Zimmermann tried to sneak a slider past him, and Johnson hit it with a thud.

“That was exactly what I wanted,” Zimmermann said. “He hit it off the end. I got a groundball. Just in the wrong spot.”

The ball squeaked through the middle, spinning past Danny Espinosa’s lunging attempt and into center field. Freeman and Gattis rumbled home and the Braves led, 2-0.

Atlanta added an insurance run in the eighth, when left-handed reliever Jerry Blevins entered and Freeman mashed a double to left center field. He scored when Johnson smoked a single off the outside of Blevins’s left knee. Blevins remained in the game, but the Braves had left their mark, on both him and the Nationals’ entire team. Again.