NEW YORK -- Bryce Harper got off to a loud start, tagging a longtime nemesis. Way later, he enjoyed another trot home.
Harper homered early, then doubled and scored the go-ahead run in the 11th inning on a bases-loaded walk by Jeurys Familia, sending the Washington Nationals over the ailing New York Mets 4-3 Friday night for their fifth straight win.
"I think every game against them means a lot," Harper said.
This was the first of 19 meetings this season between the teams that have traded the NL East title the last three years.
"That would've been a big win for them," Nationals manager Dusty Baker said. "It didn't take you long to see they were banged up and in trouble.
On a foggy night, Familia again had trouble finding the strike zone. He forced home a run with a walk to Trea Turner as the Mets lost for the sixth time in seven games. New York fell to 1-3 in extra innings early this season.
Star outfielder Yoenis Cespedes, shortstop Asdrubal Cabrera and catcher Travis d'Arnaud didn't start for the Mets because of injuries, on the same day they put first baseman Lucas Duda and infielder Wilmer Flores on the disabled list.
Plus, Matt Harvey wound up pitching when scheduled starter Jacob deGrom was scratched with a stiff neck. The Mets employed pitcher Zack Wheeler to pinch hit -- he doubled -- and another starter, Robert Gsellman, to pinch run.
"You've got to play with what you have, and I think we're doing the best we can right now," Harvey said.
Harper hit his seventh homer, lining a two-run drive in the first. He was 1 for 26 in his career against Harvey before connecting.
Did Harper think the law of averages was on his side?
"Never know," he said. "Might get dominated your whole life by one guy."
Harper is doing the dominating now. Bouncing back from a down year, the 2015 NL MVP is 12 for 19 (.632) with five home runs, four doubles and 12 RBIs in his last five games.
Harper used his legs to set up the tiebreaking tally.
The Nationals, the top-hitting team in the major leagues, hadn't gotten a hit since Jose Lobaton's leadoff homer in the fifth when Harper sliced a one-out double in the 11th.
After Daniel Murphy was intentionally walked by Josh Smoker (0-1), Familia relieved. On Thursday night, Familia -- who led the majors with 51 saves last year -- made his season debut after a 15-game domestic violence suspension and labored through 30 pitches, walking two.
This time, he bounced a wild pitch to Anthony Rendon and Harper hustled into third, the safe call standing up on replay. Rendon wound up walking on a full-count pitch and Turner, activated from the disabled list before the game, walked on four pitches.
"This isn't a perfect world where you can pick the perfect spot," Mets manager Terry Collins said. "He just didn't throw the ball over the plate, which is very uncharacteristic for him."
Enny Romero (1-0) got the win, and Shawn Kelley earned his third save.
Mets leadoff man Michael Conforto homered on Tanner Roark's first pitch of the game. Slumping Curtis Granderson hit an RBI single in the fourth and lined his first homer of the season in the sixth, tying it at 3.
Injured outfielder Jayson Werth sat out for Washington, catcher Matt Wieters got a day off and first baseman Ryan Zimmerman entered in the ninth. Murphy was back in the lineup after missing a game with tightness in his right leg.
Harvey pitched four-hit ball for seven innings. He hit Wilmer Difo, the second batter of the game, in the helmet with a 94 mph fastball. Difo stayed in, and Harper followed with his home run.