Adam LaRoche homered for the third straight game and knocked in two runs, and the Nationals roughed up Yovani Gallardo and the struggling Brewers, 8-2, in the opener of a four-game series.
Steve Lombardozzi added a three-run triple and Michael Morse went 2-for-4 with a pair of RBI in the sixth straight victory for the NL East-leading Nationals.
Edwin Jackson's (6-6) seven scoreless innings on the hill were overshadowed by the offensive outburst. The right-hander scattered eight hits and one walk while also scoring twice in the rout.
"Jackson was just spectacular," National manager Davey Johnson said.
Gallardo (8-8) only lasted five innings after getting touched for seven runs on seven hits and a pair of walks.
"He was not consistent with his command," Brewers manager Ron Roenicke said of his starter.
The rough outing came the same day reports surfaced the Brewers, who have dropped a season-high seven straight to fall 10 games under .500, were looking to move ace Zack Greinke before next week's trade deadline.
The Nationals, currently on the opposite end of the spectrum at 20 games over .500, jumped in front Thursday behind a four-run second inning, which started with LaRoche launching his 19th home run of the season.
A pair of two-out walks around a Jesus Flores single loaded the bases later in the frame for Lombardozzi, who recorded his first career triple with a line drive down the right-field line.
Three more runs in the fifth extended the lead to 7-0, as Ryan Zimmerman, LaRoche and Morse each drove in a run.
"It's good to have the offense come out and explode like they did," Jackson said. "That gives you motivation to want to come out and pound the strike zone."
Morse continued the explosion by knocking in Zimmerman with a two-out single in the eighth, and Carlos Gomez capped the scoring with a two-run homer off Henry Rodriguez in the bottom half.
The last time a Washington-based MLB team was 20 or more games above .500 was at the end of the 1933 season...Nationals shortstop Danny Espinosa went 0- for-4 top snap an 11-game hitting streak...Brewers reliever Jim Henderson, drafted in 2003 by the Nationals' organization when it was known as the Montreal Expos, hurled a perfect sixth in his big-league debut...Aramis Ramirez had two of Milwaukee's nine hits.