WASHINGTON -- The Nationals have cruised to National League East titles the past two seasons and entered this year as favorites to win a third straight. If this weekend series against the Mets is any indication, a three-peat will not come easily.
New York completed a three-game sweep of Washington with a 6-5 victory, thanks to Yoenis Cespedes' run-scoring single off right-hander Brandon Kintzler in the 12th inning as Sunday night turned into Monday morning. It was the Nationals' fifth consecutive loss after starting the season 4-0, dropping them under .500 for the first time since August 2015.
Bryce Harper continued his fast start, however, by going 3-for-4 with a pair of walks, starting the game with a two-run home run off Matt Harvey in the first inning. It was Harper's Major League-leading sixth homer. Despite his effort and six scoreless innings from the bullpen, the Nats were swept by the Mets for the first time since Sept. 7-9, 2015.
"That's part of the game," Harper said. "Sometimes you don't get it done, and tonight we didn't get it done. Good Mets team over there. They got the job done tonight. That's how it goes sometimes."
• Harper launches MLB-leading 6th home run

Starter Tanner Roark was effective at times, but he surrendered a grand slam to Adrian Gonzalez and a solo home run to Asdrubal Cabrera to give up five runs in five innings.
"It's early, so we're not worried," Roark said. "We know the type of group we have here. It's a little frustrating, just getting swept. But it's early, and we'll come back tomorrow."

The Nationals have played a bit uncharacteristicly during this losing skid, and several mistakes Sunday night came back to bite them. Trea Turner got caught in a rundown between third and home in the fifth, Anthony Rendon got picked off at first base in the eighth and the Nats struck out twice with the bases loaded in the ninth.
Those all contributed to the losing streak extending to five games, which is already longer than any losing stretch for all of last season.
"There's nothing I would change," manager Dave Martinez said. "These guys are doing well. They're all contributing in some way or form. We're just not getting that one, big clutch hit. But we're hitting the ball hard. I just got done telling all of them, 'Keep your heads up because when this thing turns around, it's going to be awesome.'"

MOMENTS THAT MATTERED
Lugo escapes bases loaded jam: The Nationals had a prime scoring opportunity to win the game before it advanced to extra innings. Harper began the ninth with a leadoff walk, advanced to second on an errant pickoff throw and then got to third a flyout to center field. But Mets manager Mickey Callaway elected to intentionally walk Howie Kendrick and Turner to load the bases. Then, Seth Lugo struck out both Michael A. Taylor and Pedro Severino to escape the jam.

Cespedes puts Mets ahead Even though Martinez would have likely preferred to stay away from Kintzler on Sunday, he turned to him in the 12th inning. Pinch-hitter Juan Lagares started the rally with a single and after a sacrifice bunt got him to second base, Martinez elected to walk Michael Conforto to set up the double play and get to Cespedes. But Cespedes singled into left-center field, allowing the run to score and putting New York ahead.
"Looking for a double play. Kintzler gets a lot of ground balls," Martinez said. "Heck, he got in there. He blooped a hit, but he broke his bat. That's what we were looking for. Unfortunately, he's a strong man, so he blooped a hit in."

SOUND SMART WITH YOUR FRIENDS
Harper began his career 0-for-21 off Harvey. He has since gone 5-for-11, including three hits Sunday.
MITEL REPLAY OF THE DAY
The Mets nearly committed a critical gaffe in the bottom of the 10th, when Gonzalez made a diving stop of a Harper ground ball, climbing to his feet and flipping it to Lugo. But as he moved to cover first base, Lugo dropped the ball, diving to grab it with his throwing hand as he kept his foot on the base. The Nationals challenged, unsuccessfully.

WHAT'S NEXT
Max Scherzer will make his second consecutive start against the Braves when Washington opens a three-game series with Atlanta at 7:05 ET Monday night at Nationals Park. During an uncharacteristic outing last week in Atlanta, the Braves ran Scherzer's pitch count up to 110 and scored five runs (two earned) in five innings.
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