Ryan Zimmerman and Ian Desmond hit three-run home runs, while Gio Gonzalez picked up his major-league leading 20th win, as the Washington Nationals ripped the Milwaukee Brewers, 10-4, in the second edition of a four-game set.
Adam LaRoche homered among his three hits and drove in two for the Nationals, who recovered from a 4-2 defeat in Friday's series opener to win for the third time in five games overall.
Gonzalez (20-8) yielded two runs and three hits in seven strong innings to become the first Washington left-hander to win 20 since Earl Whitehill in 1933. He also fanned five, becoming the first Washington-based pitcher to strike out 200 batters in a season since Walter Johnson in 1916.
"It doesn't feel like a 20th win for myself. It feels like a 20th win for the team," Gonzalez admitted. "This is a childhood dream, but to do it with a team like this, that's in first place, makes it that much better."
The Nats, who already clinched a playoff berth, saw their magic number to win the NL East reduced to six.
Taylor Green hit a late two-run shot for the Brewers, whose six-game win streak came to an end. Milwaukee fell 2 1/2 games behind St. Louis, which won at Chicago earlier Saturday, in the race for the final NL wild card slot.
Wily Peralta (2-1) lasted just 2 2/3 frames, allowing five hits and three runs, with four walks and as many strikeouts.
Already up by three, the hosts' advantage ballooned to 9-0 in the fourth facing former Nats pitcher Livan Hernandez. Jayson Werth singled and Bryce Harper walked and both scored on Zimmerman's three-run shot to left. LaRoche and Michael Morse followed with singles and Desmond chased them home with another three-run homer.
Milwaukee got on the board with two in the sixth on Ryan Braun's groundout and an Aramis Ramirez sacrifice fly, but LaRoche began the home half with a long homer to center for a 10-2 score.
In the ninth, Jeff Bianchi singled with one out and Green's homer cut the deficit to 10-4.
Right now, I really don't feel like we'd have to win every single game the for the rest of the season. But I tell you what: -- we better win almost all of them," Brewers manager Ron Roenicke said.
Washington picked up three runs in the third on RBI doubles from Harper and LaRoche, plus a Jean Segura throwing error on a Desmond single that allowed LaRoche to cross the plate.
Washington has won four of six against Milwaukee this season ... LaRoche's homer was the Nationals' 179th of the season, setting a new Nats/Expos franchise record ... Bob Porterfield was the last pitcher to win 20 games on a Washington-based club, going 22-10 for the AL Senators in 1953 ... Werth and Harper both finished with two hits and two runs scored, while LaRoche crossed the plate three times ... Hernandez was torched for five hits and six runs while recording just two outs in relief of Peralta.