WASHINGTON -- The Atlanta Braves still lead an NL wild-card race they already should have clinched.
Atlanta's offense was shut down Saturday by Chien-Ming Wang, who also drove in a run with his first career hit in a 4-1 victory.
With St. Louis rallying in the ninth inning to beat the Chicago Cubs, the Braves' lead over St. Louis was cut to two games with four remaining.
"It's another day knocked off the schedule," said Freddie Freeman, who homered for the Braves. "Obviously we're scoreboard watching."
Atlanta lost for the 16th time in its last 26 games.
"We've got to win ballgames," Braves manager Fredi Gonzalez said. "It's nice to watch the scoreboard and do all that kind of stuff, but we've got to win our games that are in front of us."
Making his 11th start since returning from a two-year layoff after shoulder surgery, Wang (4-3) allowed one run and four hits in six innings and lowered his ERA to 4.04. He struck out four and walked none.
"We couldn't figure him out," Freeman said.
Wang's RBI single off Brandon Beachy (7-3) capped a three-run fourth that put the Nationals ahead 4-0. He had been 0 for 32 at the plate in his career.
Danny Espinosa also hit a two-run single in the inning for Washington, which has won six of its last seven.
Drew Storen pitched the ninth for his 41st save.
Wang never allowed more than one runner in an inning and also got help from his defense. The best play came at the end of the third inning, when centerfielder Rick Ankiel made a running catch at the warning track with his back to the infield on a fly ball by Michael Bourn.
Freeman's leadoff homer in the fifth tied Espinosa for the lead among NL rookies at 21.
Beachy struck out nine, but allowed four runs, five hits and four walks in six innings.
"At times, I feel really good. I feel dominant," he said. "Everything I'm throwing up there goes where I want it to, and then the next batter it's gone. I just have to find that consistency."
Beachy is 0-1 with a 5.27 ERA in his last five starts.
"That's the growing pains of a young pitcher," Gonzalez said. "Sometimes you sit around and forget this is his first year in the major leagues, he's pitching in a pennant race, trying to learn and trying to get better."
Atlanta put runners on the corners with one out in the eighth. Bourn, who leads the majors with 58 stolen bases, was thrown out attempting to steal second base by catcher Ivan Rodriguez. Martin Prado then flied out.
"We just didn't get anything going offensively," Gonzalez said. "They did a nice job of keeping us off balance."
Atlanta activated RHP Kris Medlen from the 60-day DL. Medlen had elbow ligament-replacement surgery in August last year. OF Matt Young was designated for assignment. ... RHP Tim Hudson, who was taken to a hospital Friday night to be treated for a cramp, was released after receiving fluids. ... Nationals C Ivan Rodriguez started for the first time since July 4. He went 1 for 2 with a single and threw out two attempted basestealers. The 39-year-old missed nearly two months with an oblique strain before returning in early September. Washington manager Davey Johnson said Rodriguez would also start the team's final game Wednesday in Florida. ... Atlanta LHP Mike Minor (5-2) will start in the final game of the three-game series against Nationals LHP Ross Detwiler (3-5).