Maybe it was the opposing pitching, notably former Met Trevor Williams and an assortment of relievers, not looking sharp.

Maybe it was the Brandon Nimmo gnome that debuted in the dugout and looked over the club.

Maybe — probably — it was the simple fact that this lineup is much better than it had shown in the past couple days and was bound to break out in a big way.

Regardless of the rationale, the recently offensively-challenged Mets out-hit their mistakes — and there were plenty — in a back-and-forth, 9-8 win over the Nationals in front of 20,726 at Citi Field on Thursday night.

The Mets (15-11) snapped a four-game losing streak that represented the longest of Buck Showalter’s tenure with the club and inspired some hope ahead of a four-game showdown with the Braves.

The Mets, who had scored one total run in the previous two losses against Washington (9-15), scored three runs apiece in the fourth and sixth innings, which was not enough because their defense and pitching allowed Washington back into the game.

Tommy Hunter and Brooks Raley combined to hit three batters in the eighth inning, when the Nationals scored five runs thanks to the series of pitching misses, Francisco Lindor booting a grounder and CJ Abrams crushing a grand slam. Suddenly, a 7-3 Mets lead was an 8-7 Mets deficit.

But on a night on which the Mets finished with 16 hits and everyone in the starting lineup reached base safely, the top of the lineup went to work.

In the bottom of the eighth, Starling Marte knocked a single, stole second and moved to third on Lindor’s long flyout. Pete Alonso drilled a double into the right-center-field gap to tie the game before Jeff McNeil one-upped him with a triple that scored the go-ahead run.

David Robertson secured his fifth save of the season, saving face after the bullpen’s eighth-inning meltdown.

For seven innings, it had seemed as if there would be little drama because the Mets just kept hitting.

Third baseman Brett Baty reached base four times, knocked a career-best three hits and blasted his first home run of the season. Baty’s fourth-inning dinger, against a slow curveball from Williams, put the Mets up 2-1, a lead they would hold until the eighth.

Baty led the way, but he had company. Left-side-of-the-infield partner Lindor swatted a two-run double down the first-base line in the fourth inning that turned a 2-1 Mets edge into a 4-1 lead.

After the Nationals responded by scoring two against Joey Lucchesi and Hunter in the top of the sixth to close the gap to one run, Lindor blasted an RBI double off the right-field wall to drive in Brandon Nimmo. After RBI singles from Alonso (who snapped an 0-for-19 skid) and Daniel Vogelbach, the Mets swelled the lead on a night the ball kept finding holes.

Maybe they could credit a good-luck charm. Shortly before the game started, Luis Guillorme placed a large gnome — wearing Nimmo’s uniform and smile with a pointy cap — at the end of the dugout, and maybe gnomes portend well even outside of gardens.

Whatever the reason, the Mets snapped out of a funk and snapped a losing streak.