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Going into the final month of the season, the Washington Nationals have a shot at a wild card berth, but hopes are begin to fade after a loss like Saturday night to the New York Mets.

Ross Ohlendorf tries to get the Nationals back on the winning track Sunday when he takes his perfect record into the finale of a three-game series.

The Nationals enter the day 7 1/2 games behind Cincinnati for the second wild card spot in the National League.

Ohlendorf, who has pitched in 12 games and has made four starts, has yet to lose this season. The 31-year-old right-hander allowed only three hits and a run over five-plus innings of a home win against Miami Tuesday. He has an inflated 10.20 ERA in five games (2 starts) all-time against the Mets, but has yet to record a decision.

Ohlendorf's last two games have been starts, both since coming off the disabled list with right shoulder inflammation.

Jonathon Niese, who is coming off a three-hitter against Philadelphia Tuesday in the second shutout of his career, counters for the Mets. Niese is 3-0 over his last five starts and hasn't lost since June 15 against the Cubs. The southpaw is 3-0 with a 2.37 ERA in six starts versus Washington.

The Mets will try to complete the sweep tonight after posting an 11-3 win last night.

Omar Quintanilla, Daniel Murphy, Juan Lagares and Eric Young Jr. had two RBI apiece while Ike Davis, Matt den Dekker and Zack Wheeler each drove in one run for the Mets, who have won three straight.

Davis left the game with a strained right oblique.

"I feel terrible for Ike," Mets manager Terry Collins said. "He went to the minor leagues, he worked very hard on some things and came back. We started to see some signs. The 2013 year has been real frustrating for Ike Davis."

Wheeler (7-3) gave up two runs on five hits and a walk over 6 2/3 innings.

Jayson Werth, Denard Span and Ian Desmond all drove in a run for the Nationals, who have lost the first two games of this three-game set. Span is on a 14-game hitting streak.

Dan Haren (8-12) struggled through 2 2/3 innings, allowing seven runs on nine hits to suffer his first loss since July 22.

"We know what we're up against," Haren said of the team's facing playoff chances. "Everyone is pretty down in here right now. It stinks tonight, but we'll be ready to play tomorrow."

The teams have split 14 meetings this season.