Maxwell came into the game batting .132 this season and had eight homers in his previous 107 Major League games. Now a third of his total is made up of grand slams.
"I tried not to think about it," Maxwell said of coming up with the bases loaded. "I was just trying to put a ball in play, and it turned out that I got a pitch over the plate."
This grand slam came in the second inning, and the Nationals made it stand up for a
4-2 victory that gave them the series and hurt the second-place Braves' chances of catching the Phillies in the National League East.
Atlanta, which has the best home record in the Majors, hadn't lost a series at Turner Field since April, when Philadelphia also won two of three games. The Nationals are 8-7 against the Braves and 5-7 vs. the Phillies with nine games against the contenders remaining.
Maxwell doesn't relish the title of spoilers.
"I don't like it when people say that because that's where we want to be," said Maxwell, referring to the role of the Braves and Phillies as contenders. "Hopefully next year we're in their shoes. ... We're just trying to finish strong. ... Learning how to win is the main thing for us."
Minor retired the first four Nationals hitters before loading the bases on a double by Mike Morse, a single by Wilson Ramos and a walk to Alberto Gonzalez. Then Maxwell, getting a start in left field and batting eighth with a lefty pitching, made Minor (3-1) pay -- and dearly.
Maxwell picked on a 1-and-0 fastball and pulled a line-drive shot over the left-field fence not far from the foul pole.
"It was a little up and more middle than in," Minor said of the pitch.
Maxwell, 26, had only two homers and six RBIs in his previous 52 games with the Nationals this season, spending part of the year in the Minors.
"It's always extra incentive any time you get to hit," Maxwell said. "When you're in the moment, you just try to slow everything down and not think about anything at all."
Maxwell's first Major League hit was a pinch grand slam, connecting in the third at-bat of his career against Florida on Sept. 11, 2007. Then he hit a walk-off grand slam against Mets closer Francisco Rodriguez to give the Nationals a dramatic victory in their final home game last season.
"Maxie is such a class individual. He's a guy you pull for and have patience with because he is all about the team," Riggleman said. "He goes through struggles, but anything we call on him to do, whether it is pinch-running or playing defense, he's got a great frame of mind.
"I think he knows he can hit. [We're] just trying to figure out what's holding him back. He works on it constantly, and today the dividends paid off. He's a special athlete, and we're still hoping he puts it all together."
The last previous Major Leaguer to get three grand slams in his first nine homers was David Eckstein, the brother of Nationals hitting coach Rick Eckstein. The last to hit three homers in his first four career plate appearances with the bases loaded was Shane Spencer of the Yankees in 1998.
The Nationals were shut out by Derek Lowe in the series opener on Monday, but their pitching outshined the Braves in the final two games. Livan Hernandez had a scoreless outing on Tuesday and Washington's pitchers were tough again Wednesday.
John Lannan (8-7) had pitched well since coming back from a July stay in the Minors, going 5-2 with a 3.08 ERA in the eight previous starts, and he had his 10th quality start against the Braves.
Pitching out of jams when needed, Lannan worked six innings. He allowed eight hits, walked three and struck out six.
The Braves scored in the fourth inning on a groundout after Matt Diaz followed a leadoff walk with a double, and added a run in the fifth on Omar Infante's double before a single by Martin Prado.
After Lannan exited, Sean Burnett and Drew Storen shut down the Braves the rest of the way.
Burnett got out of a jam inherited in the seventh inning after Joel Peralta gave up a double that center fielder Nyjer Morgan lost in the sun, then pitched through the eighth with the help of a double play.
Storen worked the ninth and got his fourth save, retiring the Braves in order on two grounders and a strikeout of pinch-hitter Brian McCann.
"I took a new approach and didn't try to strike everyone out," said Storen, happy to get the two early grounders.
After Monday's defeat in the series opener, the Nationals had lost six straight -- tying their season high. Now, they have some positive momentum.
"Hopefully, we'll got into Philly this weekend and do the same thing," Lannan said.