WASHINGTON -- On his first swing back from a knee injury, Bryce Harper hit a curtain-call home run.
Welcome back, slugger.
"Typical Bryce right there, he's all about the drama," teammate Jayson Werth said. "He didn't disappoint us, I guess."
It was the 20-year-old Harper's only hit of the night, but the domino effect was real. Werth, unhappily bumped to second in the lineup because of Harper's return, got five RBIs. Starting pitcher Jordan Zimmermann was an unexpected offensive juggernaut with a team-high three hits, including a double to start a five-run third inning and a single to open a two-run fourth.
Put it all together and the Nationals had their second runaway win in as many days. After toying with .500 for the entire month of June, Washington moved two games above the break-even mark for the first time since late May.
"It's kind of contagious. Everybody knows we've got some work to do," Washington manager Davey Johnson said. "Let's get down to business. Let's get serious."
Harper missed 31 games with bursitis in his left knee -- the most lingering fallout from his collision with the Dodger Stadium wall -- and was activated from the 15-day disabled list before the game. Batting third and playing left field, he launched the second pitch he saw, a fastball from Yovani Gallardo (6-8), into the visitors' bullpen beyond left field for an opposite-field homer.
Harper raised his right arm and pointed to the fans as he finished his familiar sprint around the bases. After lots of high-fives in the dugout, he returned to the top of the steps and gave a thumbs-up curtain call.
"I felt like I was back on Opening Day," said Harper, who homered in his first two at-bats of the season. "I was trying to get something I could drive. I got a pitch I could handle a little bit and put it where I wanted to."
The solo shot was Harper's 13th homer of the season and 24th RBI. He hurt his knee in the mishap in Los Angeles on May 13 and reinjured it several times over the following two weeks before going on the disabled list. He went 4 for 11 in minor league rehab games last week.
He finished 1 for 4 with a walk on Monday. He slid hard into second base on a double play in the sixth inning, showing no signs of being gimpy in his knee.
The Nationals improved to 26-19 when Harper plays; they are 16-21 when he doesn't. He and the teammates made life easy for Zimmermann (12-3), who had an 8-0 lead at one point and pitched six innings. He allowed four runs and tied unbeaten Max Scherzer of the Detroit Tigers for the major league lead in wins.
Zimmermann said his night at the plate was better than his night on the mound. He joked about the size of his bat, initially claiming it was 39 inches instead of 34.
"I pitch all right," Zimmermann said. "But definitely three hits is awesome."
Werth's mood, by contrast, was nowhere near jovial, especially for a player with his best RBI game since 2009. He kept reporters waiting for nearly an hour after the game and proclaimed himself "just a grunt out here playing ball."
"I don't necessarily like hitting second," Werth said. "But if that's the best for our team, I've said it before: Last year when I led off, it wasn't personally the best fit for me, but it was the best for our team and that's why I felt like it should have happened. And the same goes for me hitting second now."
The Nationals, perhaps finally finding their stride after a middling first half of the season, have won five of seven to pull within six games of the first-place Atlanta Braves in the NL East. Washington scored a season-high 13 runs on Sunday against the New York Mets.
Meanwhile, the Brewers, missing injured slugger Ryan Braun, have lost six straight and are 32-49 at the midpoint of their season.
Gallardo struggled for the second straight start. With the Brewers' bullpen spent after Sunday's 14-inning loss to Pittsburgh, the right-hander was left to fend for himself until he was pulled in the fourth inning. He allowed eight runs, and his ERA rose from 4.20 to 4.78.
"You don't expect to see it from Yovani because he's been so consistent through his career, but he's at a point right now where for some reason he's deep in counts to almost every batter," Milwaukee manager Ron Roenicke said. "We're 3-2 and he's having to make a great pitch, and you can't survive if you keep doing that."
Johnson said LHP Ross Detwiler had a good bullpen session and is on pace to start Wednesday as scheduled. Detwiler had stiffness in his lower back after his last start. ... The Nationals optioned RHP Erik Davis to Triple-A Syracuse to make room for Harper. ... Brewers RHP Kyle Lohse will make his next start Wednesday on two days rest. Lohse started Sunday, but he went only 1 2/3 innings before a 2-hour rain delay.