• Hunt for October: New York's magic number remained at five and its lead in the division dropped to two games over idle Philadelphia.
• A bad start: Mike Pelfrey took the loss after allowing six earned runs on five hits and five walks in just five-plus innings. Pelfrey was 3-0 with a 3.31 ERA in his previous three starts.
• Quotable: "It's embarrassing with the season on the line to go out there and get embarrassed on your own home field." -- David Wright, who had three hits for the Mets
• Figure this: Moises Alou extended his club-record hitting streak to 28 games with a sixth-inning double for the Mets.
-- ESPN.com news services
Nationals 13, Mets 4
NEW YORK (AP) -- The New York Mets wanted to get off to a fast start on their season-ending homestand.
By the end of the night, they just wanted to move on.
"It's over now," New York manager Willie Randolph said. "We have to get ready for tomorrow."
New York's magic number remained at five and its lead in the division dropped to two games over idle Philadelphia. The Mets play the Nationals again Tuesday while the Phillies host Atlanta in the opener of a three-game series.
"It's embarrassing with the season on the line to go out there and get embarrassed on your own home field," said David Wright, who had three hits.
Carlos Delgado went 2-for-5 and Moises Alou extended his club-record hitting streak to 28 games with a sixth-inning double for the Mets, who had won four of five. Alou also committed an error in left that allowed a run to score in the fourth.
"We're not going to roll over," said Nationals manager Manny Acta, the Mets' third base coach the previous two seasons. "I still think they have the best team in our division. If I'm going to pick a situation I'll pick their situation, two games up with [six] games to play."
The Mets, coming off a 4-3 road trip, couldn't overcome a sluggish outing by right-hander Mike Pelfrey in the first of seven straight at Shea Stadium to close out the regular season.
"I let the team down," Pelfrey said. "I didn't keep us in the game."
The Nationals pushed across two in the fourth and three in the fifth before they chased Pelfrey (3-8) during a two-run sixth. Pelfrey was 3-0 with a 3.31 ERA in his previous three starts but struggled with his control against Washington.
"We all know that we're playing these guys and the Phillies to end the season," said Kearns, whose team travels to Philadelphia after the series against New York. "I always enjoyed playing these teams because they are teams that could be in the playoffs. You realize what you have to do to win and how important every pitch and every out is."
Pelfrey issued two more walks before departing with two outs in the sixth. Joe Smith relieved and allowed Belliard's two-run double to left-center.
Pelfrey finished with a career-high five walks, one intentional. He also hit a batter with a pitch and allowed five hits and seven runs, six earned.
"I got what I deserved," he said. "I started falling behind guys and I was walking guys, putting guys on, and they made me pay."
Belliard also hit an RBI double off Guillermo Mota during Washington's three-run eighth. He is batting .345 (30-for-87) with 15 RBIs this month.
Paul Lo Duca singled home Alou in the sixth, and Chico departed with runners on first and second and one out. Saul Rivera walked pinch-hitter Shawn Green, loading the bases, and Jose Reyes' run-scoring groundout cut it to 7-3.
"Chico started very shaky," Acta said. "After we gave him those runs, he got into the strike zone and made some good pitches."
Mets OF Marlon Anderson's appeal of his two-game suspension will be heard Wednesday. Anderson was ejected in the ninth inning of a 5-3 loss to Philadelphia on Sept. 15 and threw his batting helmet toward the plate after he reached the dugout. ... Nationals RHP Shawn Hill was scratched from his final start of the season and will have operations on his right arm and left shoulder. LHP Mike Bacsik will start Wednesday night against the Mets in place of Hill. ... Wright extended his hitting streak to 11 games and Castillo bumped his up to 10. ... Zimmerman extended his hitting streak to 11, tying the team's season high.