ATLANTA -- The Atlanta Braves aren't blaming their free-fall toward .500 on a troubling string of injuries and illnesses.
Manager Fredi Gonzalez said the excuse isn't valid when the teams beating the Braves also have injury woes.
Bryce Harper hit his second homer in two days, Gio Gonzalez gave up only one hit in seven innings and the Washington Nationals beat Atlanta 7-2 on Sunday night to complete a three-game sweep.
Washington's first sweep at Turner Field in three years left the Braves with a seven-game losing streak, their worst skid since dropping nine straight in 2010.
The Braves are struggling without Chipper Jones, who was placed on the 15-day disabled list with a left leg contusion on Saturday. Catcher Brian McCann, who did not play, has not started a game in a week due to an illness. First baseman Freddie Freeman was held out with ongoing vision problems.
"I know we've got injuries," second baseman Dan Uggla said. "Everybody's got injuries. You've got to battle through it."
Fredi Gonzalez said the Nationals are stretching their lead in the NL East despite having Michael Morse, Wilson Ramos and Jayson Werth on the disabled list.
"There are no excuses," said Fredi Gonzalez. "Look at their DL. Look at the DL of the (Cardinals) who are coming in tomorrow."
The Braves (26-23) have fallen from first place to fourth with the losing streak.
"I come in every morning and look at the stat pack and you see the division is still up for grabs," Gonzalez said. "We've got more than 100 games left."
The Nationals took the lead with four runs in the sixth. They scored at least seven runs in each game of the series.
At 29-18, the Nationals moved 11 games over .500 for the first time since their 2005 inaugural season in Washington.
Gio Gonzalez (7-1) struck out 10 and outpitched Brandon Beachy (5-3) in the matchup of ERA leaders.
Gonzalez gave up two runs and three walks in seven innings. Craig Stammen allowed two hits in 1 2-3 innings before Sean Burnett recorded the final out.
Beachy's 1.77 ERA, the best in the major leagues, did not change as he permitted three runs - only one earned - on three hits and four walks in five-plus innings. He was pulled with the game tied at 2 after hitting Danny Espinosa with a pitch to open the sixth.
"I just took a few steps backward from where I want to be tonight," Beachy said. "I didn't control my fastball, and it caused a lot of problems.
"The team put me in position where we could win the game. I didn't execute."
The Nationals jumped on former Washington pitcher Livan Hernandez following Beachy's exit. Hernandez walked Rick Ankiel on four pitches before Jesus Flores gave Washington the lead with an RBI single. Steve Lombardozzi added a two-run double.
The losing streak is having a toll on Braves fans, who booed after the hit by Lombardozzi. There were more boos from the crowd of 38,543 after Lombardozzi scored easily from second when right fielder Jason Heyward bobbled Ryan Zimmerman's single.
Flores had three hits. He left the game following his third hit in the seventh.
Harper hit his fourth homer, a high shot into the right-field seats, off Hernandez in the eighth.
Harper had two hits, stretching his hitting streak to seven games. He is hitting .287 with four homers in 27 games.
"I feel really comfortable up there right now," Harper said. "I'm not trying to do too much. ... Having guys hitting around me has been huge. We've been scoring a lot of runs."
The Braves scored a run without a hit in the first. Michael Bourn walked, stole second, moved to third on Tyler Pastornicky's sacrifice and scored on Martin Prado's groundout.
Atlanta added a run in the third. Bourn had a one-out triple for Atlanta's lone hit off Gonzalez and scored on Pastornicky's suicide squeeze.
Washington scored two unearned runs in the fourth. The Nationals loaded the bases on walks to Adam LaRoche and Espinosa and a throwing error by Pastornicky on Ian Desmond's grounder to shortstop. Flores drove in LaRoche with a single, and Gonzalez hit a sacrifice fly.
Pastornicky had another error in the seventh when he bobbled a grounder by Ankiel.
Third baseman Juan Francisco did not start but had a pinch-hit single off Stammen in the eighth. Fredi Gonzalez said Francisco "tweaked something" on Saturday, when he had three hits.
Washington's only other sweep this season came in a weather-shortened series. The Nationals won two games against Miami on April 20-21 before the third game was postponed due to rain.
NOTES: The Nationals had been 0-9 this season when closing out a series with a sweep on the line. ... Plate umpire Kerwin Danley went down to the ground in the third inning after he was hit in the groin area when a pitch from Beachy bounced past C J.C. Boscan. Danley remained in the game following a visit from Braves assistant trainer Jim Lovell. ... The last time the Nationals were 11 games over .500 was July 25, 2005, when they were 55-44. ... The Braves will open a three-game home series against St. Louis on Monday with RHP Tommy Hanson facing RHP Lance Lynn. The Nationals open a series at Miami on Monday. RHP Jordan Zimmerman will face RHP Carlos Zambrano.