WASHINGTON -- Elijah Dukes pumped his chest with his right fist and gleefully trotted to first base, happy to prove an old baseball maxim: A walk is as good as a hit.
"I'm always proud of a walk. I love walks," Dukes said. "That's my motto: A walk's as good as a hit. And I showed them today. ... You don't always have to get a hit. Sometimes a walk will beat a team, too."
Anderson Hernandez started the decisive rally by drawing a leadoff walk off Vladimir Nunez (0-2) and went to second on a passed ball by catcher Brian McCann. Cristian Guzman lined an infield single off the glove of first baseman Martin Prado, sending Hernandez to third, and Ryan Zimmerman was intentionally walked to load the bases.
Lastings Milledge struck out and Ronnie Belliard lined out before Dukes took a low and outside 3-2 slider to force in the winning run.
When Braves manager Bobby Cox summoned Nunez to work the 10th, Nationals hitting coach Lenny Harris made sure his hitters knew Nunez would attack them with an array of breaking stuff. Harris' instructions: Be patient.
"They worked the count, a full count, and were able to lay off some tough pitches when those times, a lot of people just want to get the hit to win it," Washington manager Manny Acta said.
Steven Shell (1-1) pitched an inning for his first major league win.
Hernandez and Jesus Flores each drove in three runs for the Nationals, whose winning streak is their longest since a six-game run from July 31-Aug. 5, 2007.
"They've been playing with a lot of confidence of late," Acta said. "Right now, they're just flying high. They think they can come back and our offense is clicking."
Atlanta's Chipper Jones, who entered the game as the majors' leading hitter, homered leading off the seventh, his 20th of the season. He joins Hall of Famer Eddie Mathews as the only players in baseball history to start their careers with 14 seasons of at least 20 home runs.
"A lot of players aren't lucky enough to play this long, but I have been that lucky and relatively healthy during that run and able to produce," Jones said. "Any kind of longevity record is a feather in your cap. I've had a pretty good career. To be standing besides Eddie Mathews in another category is quite an honor."
Belliard added two RBI and Zimmerman three hits for Washington, which has won nine of 13 games against Atlanta this season.
McCann and Prado also homered for the Braves, who have lost 15 of 19. Jones, McCann and Prado each drove in two runs.
Atlanta, which twice squandered four-run leads, fell to 0-21 in one-run road games this season and is 0-28 dating to last year.
"You feel like you've got the game won. We're up 4-0, 6-2," Jones said. "Then, whatever's been happening all year reared its ugly head again. ... We couldn't get anyone out. It cost us the game."
Cox was more succinct: "It wasn't a good night for pitching."
The Braves used four doubles and an RBI single by Prado to go up 4-0 in the third. After Josh Anderson doubled for the Braves' first hit against Nationals starter Jason Bergmann, Jones, McCann and Omar Infante hit RBI doubles. Prado's run-scoring single to the alley in right-center capped the uprising.
Hernandez's two-run single made it 4-2 in the fourth.
McCann lined Bergmann's 3-2 pitch over the right-field wall leading off the fifth. Two batters later, Prado's second home run put Atlanta up 6-2 and chased Bergmann.
Bergmann went 4 1/3 innings and gave up six runs and eight hits with three walks.
Braves starter Jo-Jo Reyes appeared poised to get his first victory in 10 starts since June 13, but couldn't get through the fifth inning, when the Nationals scored five times to take the lead. Reyes was lifted after yielding singles to Zimmerman and Lastings Milledge.
Buddy Carlyle relieved and gave up an RBI double to Belliard before walking Dukes to load the bases. Flores cleared them with a game-tying, three-run double to the wall in center.
Hernandez then put Washington ahead 7-6 with a two-out, RBI single to center.
"My job is to defuse a situation rather than ignite it," Carlyle said. "Tonight, I ignited it more than defused it."
Reyes worked four-plus innings, giving up four runs and eight hits.
Belliard added a run-scoring single in the sixth for a two-run lead. Jones homered off Charlie Manning in the seventh.
Atlanta tied the game in the eighth. Pinch-hitter Greg Norton and Anderson singled before Gregor Blanco's RBI double to right. Anderson was thrown out at home trying to score.
It was Washington's ninth walk-off win and the Nationals' 12th in their last at-bat. Dukes has driven in the game-winner in three of them. ... Atlanta fell a season-low 18 games under .500.