"It's kind of the makeup of our team," Morse said. "We just never quit. ... We just kept coming, kept pushing. Lately, it doesn't matter how many runs you get, you just have to keep adding them and keep going."
Scoring early and late did the trick, earning Tom Gorzelanny his third win of the year after he even hit for himself in the wacky 10th inning that saw the Nationals bat around.
It was a no-decision for starter Jordan Zimmermann, who was steady as ever, notching yet another six-inning outing to make it a perfect 20-for-20 this season. The right-hander, who scattered four hits and one run (a David Wright solo homer), has an ERA of 0.95 over his last six outings.
"Every time you have a good start, you feel good," Zimmermann said. "I mean, you always want to carry it over to the next start, and I have a pretty good streak going right now. Everything's been working, so hopefully it continues."
His effort was nearly wasted when Mike Gonzalez, in to finish the seventh, surrendered a game-tying home run on the first pitch he threw to Ike Davis, which the Mets' cleanup hitter drove on a line just inside the right-field foul pole and over the wall.
But Ryan Mattheus and Gorzelanny held serve in the latest stages of the game while the Mets' bullpen -- which was also taxed in the teams' series last week in Washington -- faltered in the 10th.
Roger Bernadina, helping to fill the void left by All-Star shortstop Ian Desmond's stint on the disabled list that officially began Monday, singled to lead off the inning.
After the Mets failed to turn a 1-6-3 double play, the bases were loaded for Harper with one out against right-hander Pedro Beato. Harper delivered against the drawn-in infield, lacing a line drive over a leaping Daniel Murphy at second to score Sandy Leon from third. Zimmerman, up next, crushed a double to the right-center-field gap before Morse homered to blow the game wide open.
"All those pitches were over the plate, and they took advantage of them," said Beato, whom the Mets optioned to Triple-A after the game. "You try to go out there and do a job, and you fail."
The Nationals admitted afterward they were pleased to see Mets starter Chris Young leave, given the way he dominated from the second inning on. After facing seven hitters in the first, he mowed through Washington's lineup, retiring 18 of 20 hitters and surrendering only a third-inning walk to Harper and seventh-inning base on balls to Leon.
"That guy, for some reason, gives us trouble," Washington manager Davey Johnson said. "We can't seem to center on his pitches. They're 85 mph, but they must have a lot of lift on them and he locates them good. He's got that little slider and curveball. He doesn't hardly throw the curveball, but we couldn't hardly touch him. Harper got ahold of one, but nobody else could. I was glad to see him depart."
The Nats finished with more hits in the 10th than the previous nine innings combined, and they moved to 4 1/2 games up on the Braves in the National League East with the victory.
"We're a confident team," Zimmerman said. "We know if we can hang around and give ourselves a chance, that's all we need."