NEW YORK -- Add Dan Haren's pitching to Ryan Zimmerman's hitting, and Washington again looked like a playoff team. Too bad for the Nationals they can't subtract nearly a whole season's worth of muddling along.

"The math keeps getting smaller and smaller," Haren said.

Haren threw one-hit ball for six innings, Zimmerman hit another home run and the Nationals won their fifth straight game, beating the New York Mets 3-0 on Wednesday in a night full of 9/11 tributes.

The Nationals improved to 22-9 in their late charge toward a playoff spot. They remained six games behind Cincinnati for the final NL wild-card spot with only 17 to play.

"I don't know how many more games we could lose," Haren said.

Zimmerman hit his fifth home run in five games. He also stole a base, but was hit in the back by the throw and left in the bottom of the ninth. Nationals manager Davey Johnson said Zimmerman was stiff and would get treatment.

Denard Span extended his hitting streak to a career-high 22 games and Anthony Rendon added a two-run double that broke it open in the eighth inning. Jayson Werth delivered another extra-base hit and Bryce Harper beat out an infield hit after missing four games because of a sore left hip.

Haren (9-13) and the Washington bullpen held an overmatched New York lineup to three singles. The Mets started five rookies and lost for the eighth time in 10 games -- on Monday night, they were shut out on one hit by Nationals lefty Gio Gonzalez.

The Mets were mathematically eliminated from playoff contention during the day.

"I know they're young. That's all part of it," manager Terry Collins said. "But, as we said before, in the growing stages in this part of the year, we want to see some guys get better. And part of that getting better is being able to gather yourself on the side and get into the batter's box and put a good at-bat on."

Battered by the Mets and Marlins in his previous two starts, Haren dominated. He gave up a single to Juan Lagares in the fourth, struck out eight and walked one.

Haren had no complaints about getting pulled by Johnson on a humid night.

"I lost his confidence a little bit after the last two starts," Haren said. "I get it."

Xavier Cedeno, Drew Storen, Tyler Clippard and Rafael Soriano combined for three scoreless innings of relief. Soriano closed for his 41st save, giving up a bunt single to Lagares.

Zack Wheeler (7-5) gave up one run and eight hits in seven innings, striking out six and walking one. He wound up with his third loss in four starts.

Zimmerman opened the sixth by homering beyond the leap of left fielder Eric Young Jr. His 22nd home run came on an 0-2 pitch and was the first long ball permitted by Wheeler in 36 innings -- he was tagged for nine homers in his first 57 innings this year as a major leaguer.

The Reds' 6-0 win over the Chicago Cubs was already posted when the Nationals took the field. They got off to a fast start when Span led off the game with a single and Werth lined a one-out double. Wheeler escaped by striking out Harper and Ian Desmond.

Werth has gone 11 for 23 during Washington's winning streak with two homers and six doubles.

Collins wore an NYPD hat during batting practice, and there were several remembrances on the field, on the scoreboard and over the public-address system of those affected by the terror attacks 12 years ago.

Before the game, the dugouts were filled with applauding players, managers and coaches as representatives of first responders from Sept. 11 marched into the middle of the diamond. The Mets and Nationals then lined up along the baselines for a moment of silence, followed by the national anthem. A member of the New York Fire Department performed "God Bless America" during the seventh-inning stretch.

Game notes
Zimmerman was 0 for 8 against Wheeler before homering off him. ... Lagares ended an 0-for-12 rut with his single. ... Mets INF Justin Turner will be "down for a few days" with a strain in his right hamstring. He hurt himself running the bases Tuesday night. ... Mets 3B David Wright (strained right hamstring) ran the bases before the game and will increase his workouts this weekend. He's been out since Aug. 2 and there's no target date for his return. ... Nationals LHP Ross Detwiler, sidelined since early July because of a back strain, threw his second bullpen session. ... Before the game, Johnson admitted his preseason boast of "World Series or bust" had come too soon. "We had some injuries. We didn't have a lot of depth in pitching," the retiring manager said. "I wouldn't have been as cocky coming out and saying we're going to dominate and win the World Series if all those things I knew weren't set in place."