MILWAUKEE -- For the first time in 79 years, a Washington-based team is 20 games over .500.
And the Nationals say they have a lot more to accomplish.
"We haven't done nothin'," Washington manager Davey Johnson said. "We're playing good ball. We're playing good on the road. Pitching staff has been great, offense has been good, defense outstanding. That's how you win ballgames."
The Nationals have won six consecutive games, matching a season-high, and improved to 59-39. The last time a District of Columbia team was 20 games over .500 was 1933, when the American League Senators finished 99-53 and lost the World Series in five games to the New York Giants.
"It's July," Ryan Zimmerman said. "If we have the best record in September or October then we can talk about it."
Milwaukee's seventh straight loss came on the day general manager Doug Melvin acknowledged he was working to trade ace Zack Greinke, effectively signaling that the Brewers are giving up hopes of reaching the postseason a year after advancing to the NL championship series.
"We just got down early and never could get the big hit," Milwaukee manager Ron Roenicke said.
Jackson (6-6) scattered eight hits and a walk while striking out four.
"I made a couple of pitches when I needed to and had some defensive plays when I needed them," the right-hander said. "It was just a combination of both."
The Brewers were 2 for 12 with runners in scoring position against Jackson.
"Our guy was just spectacular," Johnson said. "A couple little jams and he pitched out of them. He's been pitching great all year."
The victory also allowed the Nationals to tie the New York Yankees for the best record in the major leagues.
"Those guys deserve it," Johnson said of the team's record. "They hung in there when times were really tough. Shoot, we've earned it."
Milwaukee starter Yovani Gallardo (8-8) put his team in a hole early, allowing the Nationals to score four runs in the second. The right-hander gave up seven runs on seven hits and two walks with six strikeouts in five innings.
"I just couldn't find my put-away pitch," Gallardo said.
Every Washington starter reached base except for Danny Espinosa, who went 0 for 4 in snapping his 11-game hitting streak.
Adam LaRoche homered for the third consecutive game, driving the first pitch of the second inning for his 19th home run of the year to make it 1-0.
With two outs, Roger Bernadina walked. Washington put on the hit-and-run and Jesus Flores hit a routine grounder to second, but Rickie Weeks had vacated his spot to cover second. The ball bounced into the outfield and Flores reached on a single to keep the inning alive.
Gallardo then walked Jackson to load the bases. Lombardozzi followed with a hard grounder past a diving Corey Hart at first that went down the right-field line for a triple and a 4-0 Washington lead.
The Nationals scored three more off Gallardo in the fifth. Jackson led off with a single and moved to third on a one-out single by Bryce Harper.
Zimmerman then hit an RBI single to score Jackson, and LaRoche's slow groundout to first scored Harper for a 6-0 lead.
Michael Morse hit an RBI single that drove in Zimmerman for a 7-0 lead and then added another single in the eighth that gave Washington an 8-0 lead.
Brewers reliever Tyler Thornburg left with a tired arm in the eighth inning.
"The doctors think he's fine," Roenicke said. "He's just not used to the bullpen."
Brewers C Jonathan Lucroy was reinstated from the 15-day DL and the contract of RHP Jeff Henderson was selected from Triple-A Nashville. To make room on the roster, C George Kottaras was designated for assignment and INF Jeff Bianchi was optioned to Nashville. ... Washington had lost eight consecutive games at Miller Park, but it was the first game between the teams since May 2011.
Information from The Associated Press was used in this report.