WASHINGTON — Adam Dunn hit two home runs and drove in five runs, Willie Harris hit an inside-the-park homer and Jordan Zimmermann won his first game in 15 months as the Washington Nationals sent the reeling Atlanta Braves to their fourth straight defeat, 8-3 on Friday night.

The Braves, who were swept in a crucial three-game series by first-place Philadelphia, began the day one-half game ahead of San Diego in the NL wild card race. Washington, which won its fourth straight — its longest winning streak of the season — denied retiring manager Bobby Cox his 2,500th win in his 4,500th game as a major league manager.

Dunn, who missed Thursday's game with elbow and hamstring injuries, hit both home runs off Nationals nemesis Tim Hudson.

Hudson (16-9) dropped to 10-2 against the Nationals franchise. He allowed six runs and seven hits in 5 2-3 innings. Hudson walked six, equaling his career high. His ERA against Washington rose from 1.55 to 1.91.

Dunn led off the second with a long home run to center field, his 36th of the year. He hit a two-run homer into the left field bullpen in the third for his 30th multihomer game and sixth this season. Dunn added a two-run single in the sixth off Mike Dunn — giving him 101 RBIs.

Harris hit a 3-2 pitch from Kyle Farnsworth off the wall in center field. The ball bounced hard off the wall and far from center fielder Nate McLouth, and the speedy Harris raced around the bases for the second inside-the-park home run in Nationals history and his 10th homer of the season.

Zimmermann (1-2), who missed most of this season after Tommy John surgery last July, won his first game since June 25, 2009. He threw five innings and allowed his only run on Omar Infante's eighth home run with two outs in the fifth.

Zimmermann gave up three hits, struck out five, walked one and hit a batter.

Tyler Clippard pitched two perfect innings and Joel Peralta gave up two runs in the eighth — one unearned. Jason Heyward's infield grounder bounced off Dunn's glove at first base for an error, scoring one run, and Brian McCann's RBI single drove in Infante to make it 7-3.

Sean Burnett and Miguel Batista worked the final 1 2-3 innings for Washington.

The Nationals scored their eighth run on a two-base throwing error by pitcher Billy Wagner in the eighth.