Showing an uncanny feel for the moment, Bryce Harper announced his return from the disabled list with one powerful swing of the bat, two pitches into his first plate appearance since May 26, 11 minutes into Monday’s game. And when he deposited Yovani Gallardo’s fastball over the left field wall and into the visitors’ bullpen, a Nationals Park crowd of 24,889 gleefully took him back into their warm embrace, drawing him out for a curtain call.

The crowd cheered when Harper was introduced before the Washington Nationals’ 10-5 rout of the Milwaukee Brewers on a muggy night. Some even stood, removed their hats and flashed “Welcome Back” signs when he strode to the plate in the first inning. By the time he was racing around the bases, the park was in full throat.

“We kind of expected something,” Manager Davey Johnson said. “Something he was gonna do special.”

As Harper slapped hands with teammates in the dugout after his 13th home run, the applause continued. Harper jumped to the top step of the dugout to acknowledge the crowd, the sort of dramatic return only a star like Harper could produce.

“Felt like I was back at opening day,” said Harper, who started the season at Nats Park with two home runs in his first two at-bats in the season’s first game.

The Nationals welcomed the biggest piece of their lineup back, and things felt normal again as the team moved to two games over .500 for the first time since May 28. Against the Brewers, the entire Nationals offense erupted, and it began with the 20-year-old left fielder who will be central to the team’s fortunes the second half of the season.

“Typical Bryce right there,” right fielder Jayson Werth said. “He’s all about the drama, so he didn’t disappoint us, I guess. That was good.”

Starter Jordan Zimmermann carved through the Brewers’ lineup for six innings — the first four dominant, the final two less so — and won his 12th game, tied for the most in the major leagues. A day after producing their most lopsided victory of the season, the Nationals followed with 13 hits. Their 23 runs over the past two games tied a team record for the most in a two-game span.

Werth, moved back near the top of the lineup by Johnson with Harper’s return, drove in five runs for the first time in his Nationals career. By the fifth inning, every starter notched at least one hit except for Kurt Suzuki. Even Zimmermann lashed three hits, the most of his career. Harper finished 1 for 4 with that homer and a walk.

Before the game around 2 p.m., Johnson found the familiar face in the clubhouse and the two shook hands. Johnson, perhaps the most eager to have Harper back in the lineup besides the player himself, looked at the young slugger almost in disbelief. “Is that really you?” Johnson said he asked Harper. The Nationals are 26-19 when Harper plays, 16-21 when he doesn’t.

“Just wanted to get back out there, but not anxious at all,” Harper said of his return. “I’m excited as always. I’m excited to play this game every single day. So it was great to get back out there.”

The Nationals pounced on Gallardo, the ace of a struggling team, whose trade value could be affected by each start this month. They rocked him for five runs in the third inning, a frame that began with a double by Zimmermann. Werth drove Zimmermann and Denard Span in with a double to center. Ryan Zimmerman, Adam LaRoche and Ian Desmond added run-scoring hits. The Nationals sent nine batters to the plate and had a 6-0 lead by inning’s end.

The Nationals tacked on two more runs in the fourth with Werth’s two-run single off Gallardo. Zimmermann again led off an inning with a hit, this time a single, and Span followed with a double to right. Werth worked a six-pitch at-bat before depositing a curveball into left field. He drove in another run in the eighth inning and his total of five was his most in one game in four years.

Even though rookie Anthony Rendon produced in the second spot of the lineup for the past month, Johnson chose to move Werth back near the top of the lineup to put him ahead of Harper again, a combination that worked well last season. Werth wasn’t partial to the move, preferring to hit lower in the lineup like he had. When he returned from the disabled list last season, the Nationals’ offense scored a lot of runs with him at the top of the order. Johnson wants to recapture that and wanted the veteran presences of Werth and Zimmerman around Harper.

“With everybody healthy, look at our lineup. It’s balanced,” Werth said. “It’s right-left-right all the way down. You put Rendon down in the seventh hole and it’s a tough, balanced lineup, I mean it really is. We’ll see, but I like our lineup like that. I don’t necessarily like hitting second, but if that’s the best for our team. I’ve said it before, last year, when I led off, I didn’t really, for me personally, it wasn’t the best fit for me but it was the best for our team, and that’s why I felt like it should’ve happened.”

The offensive outburst was enough to withstand Zimmermann’s struggles in the middle innings and allow him to match his career-high in wins midway through the season. Only three times has Zimmermann allowed more than three runs in a game this year and each of the times he has gotten at least a four-run cushion.

Zimmermann allowed two runs in the fifth inning. In the sixth, he allowed another two — both solo home runs on pitches left over the plate — to trim the Nationals’ lead to 8-4, and his night was done after 88 pitches. Craig Stammen gave up two hits and a run in the seventh before Johnson pulled him with two outs for Drew Storen. Zimmermann attributed any lag to the toll of running the bases three times and scoring twice on a humid night.

“You get eight runs like that and you’re just pitching to the score,” he said. “I’m throwing fastballs and trying to get quick outs and trying not to fall behind anyone. They took the fastball the other way. I was just throwing it away. ... They obviously knew I was going to throw the fastball and I wasn’t going to mess around. They were ready for it.”

Even though Harper struck out, flied out, walked and reached on a fielder’s choice in his other plate appearances, the complexion of the Nationals’ lineup felt different by his presence. The Brewers had one more potent hitter to deal with, and the rest of the Nats could lean on his fire and aggressiveness.

“Having obviously Bryce back and getting [Werth] in the two-hole and just having everybody but [catcher Wilson] Ramos” helps, Span said. “But it seemed like our lineup is a lot deeper with Bryce back, and it makes it tougher for the opposing pitchers.”