Braves catcher David Ross has a few choice words for home plate umpire Paul Schrieber in the fourth inning Tuesday. (Rob Carr/Getty Images)

It was no secret that what the Washington Nationals wanted before last Sunday’s trade deadline was a center fielder. They wanted a player with a stellar glove who could get on base and set up the offense and stabilize the leadoff spot — a position that had seen seven different Nationals this season.

But in the past month, since returning from the disabled list with a strained rib muscle in early July, Rick Ankiel has made his case to be and remain the Nationals’ center fielder and leadoff hitter — at least for the remainder of the season.

His grand slam in the fourth inning with his team trailing by a run helped power the Nationals to a 9-3 victory over the Atlanta Braves and to their fourth consecutive win.

Ankiel, a quiet player who has homered three times in two nights, happily high-fived teammate Wilson Ramos as he crossed home plate in front of 24,326 fans. He smiled broadly in the dugout for minutes after that. It was a visibly emphatic moment for a player who started the season as the Nationals’ everyday center fielder but lost the job because of injury and inconsistency at the plate.

“Just looking for a pitch to drive,” Ankiel said of his grand slam in his matter-of-fact way. “I got to 2-0 and just looking for something I can drive.”

Said Manager Davey Johnson, “I haven’t seen many balls hit that hard.”

As much as Tuesday’s game was a continued statement by Ankiel, it was also a positive sign from an offense that has scored more than five runs in a game only three times since the all-star break in mid-July. Against the Braves, the Nationals’ offense came to life, managing six extra-base hits, including triples by Jonny Gomes and Brian Bixler. All but two of the Nationals’ nine runs were scored on home runs. Three players homered, including one from an unexpected source.

“This is my kind of game,” Johnson said. “I haven’t had any of them. I’ve been here five weeks and I’ve been waiting for something like this.”

While hot-hitting Michael Morse’s solo home run in the sixth inning came as no surprise, Ian Desmond’s two-run shot in the fifth was. The shortstop hit a sinker from Atlanta starter Derek Lowe just over the left field wall for his first home run since April 28 — snapping an 80-game home run drought. Although he’s known more for his defense than his bat or power stroke, Desmond managed 10 home runs last season and four in 21 games the year before.

“It felt good,” Desmond said. “I was glad to get the RBI and drive the run in. We’ve been kind of scuffling with runners in scoring position all year and it’s nice to finally to be able participate in that. And see the offense move in the right direction, that’s good.”

The Nationals scored first in the second inning with the help of Jayson Werth, who recently has seemed to calm down at the plate. Over the past 12 games including Tuesday, he is 15 for 44 (.340). He led off the second inning with a single to right field and advanced to third base when Braves catcher David Ross threw errantly into center field trying to catch Werth stealing second. Desmond then lifted a ball to right field to score Werth.

Against John Lannan, however, the Braves knew they would have a tougher time scoring. Since the 2007 season, only one other pitcher in the major leagues has more wins against the Braves than Lannan. The left-handed starter has seven wins in that span, second to the 11 by Philadelphia’s Cole Hamels. And in his previous five starts against Atlanta, Lannan was 4-0 with a 2.89 ERA.

But despite the dominance against one team, Lannan was coming off one of his worst starts of the season, as he struggled with control, throwing 115 pitches and allowing four runs on five hits in 52 / 3 innings in a 5-2 loss to the Marlins.

On Tuesday, it was the dominant version of Lannan (8-7) who emerged. In the second inning, Lannan gave up back-to-back singles to Atlanta’s seventh and eighth hitters, Ross and Jose Constanza. Atlanta’s recently acquired center fielder, Michael Bourn, snuck a ball between Morse and the foul line and into right field, plating his first run as a Brave. Martin Prado’s groundball scored another run and put the Braves up 2-1.

But once staked to a lead thanks to Ankiel’s grand slam, Lannan calmed down. He allowed no more runs and struck out five of the next 10 batters, finishing with a season-high eight strikeouts through 62 / 3 innings.

“Once we got that lead, I told myself to attack the zone more,” Lannan said, “and let them put the ball in play.”

Henry Rodriguez, who had struggled with his control again recently, pitched 21 / 3 scoreless innings to close out Lannan’s win. But for the second straight night it was Ankiel who set up the victory.