NEW YORK — The Mets have four wins at Citi Field since the All-Star break.
The Washington Nationals have six.
And the Atlanta Braves have five.
"It's frustrating for all 35 guys in that clubhouse, besides the players, and the coaches and the front office," manager Terry Collins said after the latest lackluster effort, a 2-0 loss to the Nationals on Wednesday night. "To not play well at home, to not score runs — I was sitting around thinking about things."
John Lannan (3-0) pitched five-hit ball over 5 2-3 innings in his first start since replacing Stephen Strasburg in Washington's starting rotation, and the Nationals trimmed their magic number to five for clinching a playoff berth. Ryan Zimmerman homered in the fourth off rookie Matt Harvey (3-5), and Ian Desmond connected off Jon Rauch in the eighth.
New York finished an 0-6 homestand and dropped to 65-78, falling 13 games under .500 for the first time since finishing 2009 at 70-92. The Mets matched their longest skid of the season with the six straight defeats and have lost eight of nine overall.
They also extended their club-record streak of scoring three runs or fewer to 13 straight home games. They have lost 22 of their last 26 in Queens.
"We set the bar pretty high in April and May," Collins said. "Our club wasn't picked to be very good and we set the bar up there ... Right now, we just cannot seem to recreate what happened in April."
A 23-year-old right-hander taken with the seventh overall pick in the 2010 amateur draft, Harvey has impressed Collins since he was brought up in late July and already has earned a spot in New York's 2013 rotation.
Harvey allowed five hits in five-plus innings, striking out 10 — one short of his big league high. Washington ran up his pitch count to 106, matching his most in nine major league starts.
"This guy's taken his game to another level when he got up here," Collins said. "He's been so impressive. You know we've got something special."
Harvey's only mistake was leaving a pitch to Zimmerman over the plate in the lower part of the strike zone.
"Nobody likes to lose. Every guy in here is working his butt off," Harvey said. "I felt good early and then I think I pressed too much. That's a mistake I'm going to learn from and I regret."
Washington chased Harvey by loading the bases with no outs in the sixth.
"We lost. I didn't do my job," Harvey said. "We needed zeros."
Robert Carson relieved and retired Tyler Moore on a foulout, Kurt Suzuki on an infield fly and Steve Lombardozzi on a flyout.
"I had some nerves," Carson said. "It was my first time in that situation, coming in with the bases loaded, no outs. I was a little bit nervous, but I just tried to stay focused and tried to attack one hitter at a time. I tried to pitch to my strengths."
Lannan left in the bottom half after David Wright singled and stole second, and Lucas Duda walked with two outs. Christian Garcia hit Kelly Shoppach on the left arm with his first pitch, loading the bases, but retired pinch-hitter Ike Davis on an inning-ending flyout.
A native of nearby Long Beach, Lannan struck out two and walked one in an 81-pitch outing. Pitching before about 20 family members and friends, he made his first appearance since a minor league start on Aug. 30 and improved to 4-1 with a 1.69 ERA in his last six starts against the Mets.
"He earned a lot of respect in this clubhouse," said reliever Sean Burnett, who gave up two hits and got two outs in the ninth — his first appearance since Sept. 2 following a layoff caused by an irritated nerve in his pitching elbow.
Drew Storen came in and retired pinch-hitter Daniel Murphy on a game-ending flyout with runners at the corners for his second save,.
Washington opened an 8½-game NL East lead over the second-place Braves heading into a three-game series at Atlanta starting Friday. The Nationals are closing in on the capital's first postseason baseball berth since the original Washington Senators in 1933.
"This was a big series," manager Davey Johnson said. "We need to kind of drive the nail in their coffin over here and come into Atlanta in a good frame of mind."
NOTES: Washington has won eight in a row in Queens and 12 of 13. ... The Mets scratched Murphy from the starting lineup because of a sore back. Ronny Cedeno took his place at 2B but left in the sixth because of a tight right hamstring. ... Players' association head Michael Weiner, undergoing treatment for a brain tumor, was in the Mets' clubhouse speaking with players before the game. ... The previous big league team to score three runs or fewer in 13 straight home games was Seattle, which did it 16 in a row from Aug. 7 to Sept. 13, 2010, according to STATS LLC. ... The Mets were 1 for 8 with runners in scoring position, dropping to .201 since the All-Star break. They were at .269 in the first half.