ATLANTA — The Atlanta Braves hoped to benefit from a typical second-half surge by Adam LaRoche when they acquired the first baseman on July 31.

Right on cue, LaRoche is gaining momentum as the Braves move back into playoff contention.

LaRoche gave the Braves the lead with a seventh-inning homer, his second of the game, and Atlanta beat Washington Nationals 6-2 on Wednesday night for its fifth straight victory.

LaRoche is hitting .371 with three homers and seven RBIs in 10 games with the Braves, who set a season high with four home runs.

"It feels like I haven’t left," said LaRoche, who played for manager Bobby Cox and the Braves from 2004-06.

"Stepping back on the field, there’s no pressure to impress Bobby or the front office or my new teammates. I can go out and play my game."

Atlanta’s 17-9 record since the All-Star break is the best in the National League.

The Braves traded first baseman Casey Kotchman, who had only six homers, to Boston for LaRoche. When making the deal, general manager Frank Wren said LaRoche’s history showed he was a good bet to provide a second-half lift.

LaRoche has a career .295 average after the All-Star break, compared with .252 before the break, according to STATS.

"He’s been great," said Derek Lowe, who gave up two runs in seven innings. "I think this is what people expected when we got him, some power in the middle of the lineup."

LaRoche snapped a 2-2 tie with his seventh-inning homer off Jorge Sosa (1-1). He had a second-inning homer off Craig Stammen and drove in a third run with a bases-loaded walk in Atlanta’s three-run eighth.

"It feels good," LaRoche said of his swing. "It’s starting to come together."

Garret Anderson and Martin Prado also hit homers for the Braves, who moved into a second-place tie with Florida in the NL East.

Lowe (12-7) gave up seven hits and four walks but was helped by three double plays.

"You can learn from watching Lowe," said Nationals manager Jim Riggleman. "He gets ground balls. That’s what he’s known for. That’s how he gets out of trouble."

The Braves (60-54) are six games over .500 for the first time since finishing 84-78 two years ago. The Nationals, who had an eight-game winning streak end with an 8-1 loss to Atlanta on Tuesday night, were swept in the two-game series.

Prado increased the lead to 4-2 with his eighth-inning homer off Sean Burnett.

Burnett gave up a single to Chipper Jones and a double to Brian McCann before loading the bases with an intentional walk to Yunel Escobar. Burnett walked LaRoche to force in a run and, with two outs, Jason Bergmann walked pinch-hitter Greg Norton to force in another run.

Reliever Peter Moylan struck out Elijah Dukes with two runners on to end the eighth.

Stammen, who had a 15.32 ERA in his last three starts, gave the Nationals six strong innings on the day the team announced another rookie, Jordan Zimmermann, will have reconstructive elbow surgery next Wednesday.

Stammen gave up only four hits and two runs, on homers by Anderson and LaRoche in the second.

"It was good to get back on track a little better from my previous outings," said Stammen, who gave up only one hit after the two second-inning homers.

"I started throwing as hard as I could," he said. "I was going after them. I was a little more aggressive. ... It’s no fun giving up home runs."

Adam Dunn and Ronnie Belliard had run-scoring singles for Washington.

Braves reliever Mike Gonzalez was knocked to the ground but managed to catch a sharp liner by Josh Bard in the ninth. Gonzalez was trying to protect himself when he stuck his glove in front of his face.

"I didn’t have time to be scared," Gonzalez said. "I saw it coming right in my teeth. Oh, man, that’s why I say that prayer every time I go out."

The Nationals had runners on first and second when Nyjer Morgan was picked off first by McCann to end the game.

NOTES: Nationals hitting coach Rick Eckstein served a one-game suspension for "inappropriate actions" when he was ejected after arguing a call on the field Tuesday night. ... Guzman and Zimmerman extended their hitting streaks to 17 and 15 games, respectively. ... Braves OF Nate McLouth (strained left hamstring) missed his second straight game but hopes to return following today’s off day. ... LaRoche had his 11th career multihomer game.