WASHINGTON — Scott Olsen pitched into the ninth inning, newly acquired Nyjer Morgan had three hits and the Washington Nationals beat the Atlanta Braves 5-3 on Sunday for their second straight victory.

Olsen (2-4) allowed three runs and eight hits over 8 2-3 innings, prevailing for the first time since returning June 28 from the 15-day disabled list after a bout with left shoulder tendinitis. He walked five and struck out five.

Olsen helped his own cause with his first two hits of the season, including an RBI single.

Derek Lowe (7-7), who signed a four-year, $60 million free-agent contract with the Braves in the offseason, lost for the fourth time in his past five starts. The right-hander lasted 5 1-3 innings, allowing four runs and 10 hits.

Nate McLouth hit a two-run homer in the ninth inning to chase Olsen. Martin Prado matched a career high with four hits for Atlanta, which has dropped four straight road series.

Mike MacDougal got the final out for his fifth save.

Washington took a 1-0 lead in the first when Morgan hit a leadoff single, stole second and scored on Ryan Zimmerman's single to right. Morgan and reliever Sean Burnett came to D.C. from Pittsburgh in a trade Tuesday.

A two-run second made it 3-0. Cristian Guzman singled with one down and scored on Ronnie Belliard's two-out double to center, Belliard's first RBI since June 2. Belliard moved to third on the throw home, then scored on Olsen's bloop single to left.

Atlanta got on the board in the third when Nate McLouth singled with one out, went to third on Martin Prado's double to left and scored on Chipper Jones' sacrifice fly.

Lowe departed after loading the bases in the sixth on a Josh Bard double, a walk to Belliard and Olsen's second single. Boone Logan relieved and got Morgan to bounce into a fielder's choice forceout at home before Nick Johnson lined an RBI single to left for a 4-1 lead.

In the eighth, Morgan doubled home Belliard, who led off with a single and moved up on Olsen's sacrifice bunt.

NOTES: Before the game, the Nationals recalled RHP Jason Bergmann from Triple-A Syracuse to work out of the bullpen. ... Atlanta is 4-11 at Nationals Park since it opened last year. ... Before going 2 for 3, Olsen had been 0 for 10 with five strikeouts. ...Celebratory — but premature — fireworks erupted after Jones fouled off a 3-2 MacDougal pitch in the ninth before drawing a walk.