WASHINGTON -- The Washington Nationals used good starting pitching and timely hitting to win the first two games of this three-game series with Atlanta. They employed the same formula to complete a series sweep on Thursday.

Ian Desmond hit a two-run homer and starter Doug Fister threw seven shutout innings as the Nationals rolled past the Atlanta Braves 7-0 to match a season best with their sixth straight victory.

The Nationals (40-33) completed the three-game sweep of the Braves (35-38) and now have won eight straight against Atlanta. Washington has an 8-1 lead in the season series after holding the Braves to two runs in 29 innings during the three-game series.

"Guys are going out there ... doing things the right way together," Fister said. "That's our biggest thing. We've got some momentum together. Guys are in midseason form right now in mid-June, and that's a good thing."

Fister's seven-inning outing was his longest this season and gave the right-hander his first win since May 9. Fister (3-3) was on the disabled list (right forearm tightness) from May 15 to June 18 and gave up just four hits in his seven innings.

In addition, the right-hander struck out four and walked just one as the Braves really threatened just once.

"I thought he pitched really well, was in command out there throwing where he wanted to," Nationals manager Matt Williams said. "It was good today. Lots of 3-2 curveballs today. He got some swings and misses on curveballs, which is another weapon for him to use."

The seven shutout innings extended a strong run by the Washington starters in recent days. They have not allowed a run in 41 1/3 innings -- a franchise record, breaking the previous mark of 39 set in August 1981 when the team played in Montreal.

That's the longest run in the majors since Cleveland's starters blanked opponents for 44 1/3 innings in May 2008.

Desmond has been fighting through a long slump -- batting just .111 in his previous 15 games -- but helped the Nationals in this series.

The shortstop got the winning sacrifice fly in a 2-1 victory Wednesday and went 2-for-4 on Thursday, including his third-inning homer. He also scored two runs while his average moved up four points to .224.

"To be able to, (with) two strikes, I laid off some balls in the dirt, which has been a struggle lately," Desmond said. "I'm seeing the ball a lot better. I was able to get one out of the park today."

The Washington offense also got some help from a shaky Atlanta defense that committed three errors, which led to three runs in the first two innings and one in the eighth. Three of the Nationals' seven runs were unearned.

"You can't give a good club like this opportunities and give them outs and give them extra bases," Braves manager Fredi Gonzalez said. "They're going to take advantage of it. And they've got really, really good pitching. And they've got some guys that can swing the bats and are pretty hot right now."

The miscues made life tougher for Atlanta right-hander Matt Wisler (1-1) in just his second major league start. The errors were a big reason he allowed six runs (four earned) and nine hits in four innings, but Wisler said he needed to do better.

"It's just me not executing," he said. "It comes down to me at the end. I've got to execute the pitch to get out the inning and today, I didn't as well as I should've."

The Braves' problems began early. Center fielder Denard Span singled to start the bottom of the first, but right fielder Nick Markakis bobbled the ball for an error, ending his major-league-record streak of 398 games in the outfield without a miscue.

Span moved to second and later scored on third baseman Yunel Escobar's groundout for a 1-0 lead.

Catcher Wilson Ramos doubled to start the second and scored when third baseman Kelly Johnson made a throwing error on Desmond's grounder. Desmond later made it a 3-0 lead when he scored on center fielder Michael A. Taylor's double.

First baseman Clint Robinson made it 4-0 with an RBI single in the third. Escobar just beat the tag of Atlanta catcher A.J. Pierzynski, a play that stood after the Braves challenged.

Desmond added his two-run homer later in the inning to put Washington up 6-0.

Right fielder Matt den Dekker came into the game in the eighth and got an RBI single for a 7-0 lead. Atlanta's third error led to that run.

NOTES: Washington RF Bryce Harper and INF Anthony Rendon both did not play. Harper got a cramp while running out a double in the 11th inning Wednesday, but manager Matt Williams wouldn't say much about either player other than they're getting a day off and would be available. The skipper said Rendon was battling a "bit of an issue" with his quad. ...CF Denard Span has reached base in 18 consecutive games for the Nationals. He went 1-for-5 in Thursday's win. ... Atlanta RF Nick Markakis made an error in the first inning that ended his streak of 398 games without a miscue. He bobbled Span's single, letting him move to second. That's a major league record for outfielders; the previous mark was 392. ... Markakis banged out three hits in the first two games of the series and leads the team with 25 multi-hit efforts in 2015. That was tied for fourth best in the National League.