Patriots cornerback Marcus Jones outruns Jets safety Jordan Whitehead, left, and long snapper...

Patriots cornerback Marcus Jones outruns Jets safety Jordan Whitehead, left, and long snapper Thomas Hennessy to score the winning touchdown during the final seconds of the game at Gillette Stadium in Foxborough, Mass., on Sunday. Credit: EPA-EFE/Shutterstock/CJ Gunther

ATLANTA — The biggest series of the season will end with the biggest game of the season.

After Atlanta topped the Mets again Saturday night, 4-2, beating Max Scherzer a night after beating Jacob deGrom, the defending World Series champions jumped ahead in the NL East by one game — the largest division deficit the Mets have faced all year.

That sets up a series finale and season series finale with monumental playoff implications Sunday night.

If the Mets win that game, they will move back into a tie in the standings and, critically, earn the tiebreaker by virtue of doing better in the head-to-head matchups. Such a technicality would award them the division title if they finish with the same record as Atlanta. The Mets would control their own destiny, guaranteed to win the NL East title if they win the rest of their games.

But if the Mets lose, Atlanta will be up two games and own the tiebreaker with three to play. The magic number would be one.

The NL East winner will get a bye into the NLDS and five days off after the regular season. The second-place finisher will play in the best-of-three wild-card round at its home ballpark next weekend.

These clubs have played 18 times. Each team has won nine games. Game No. 19 will feature the Mets’ Chris Bassitt (15-8, 3.27 ERA) versus Atlanta’s Charlie Morton (9-6, 4.29).

 

“Everybody knows what’s ahead of them — and what was when we got here,” manager Buck Showalter said. “So does Atlanta. That’s why you got two really good teams competing very late in [the season]. It means a lot to both teams. You have to turn the page emotionally and mentally and get ready for the next challenge.”

Scherzer said: “As the saying goes, you’re only as good as your next day’s starting pitcher. And Bassitt has been really good for us this year. We need him to go out there and do his thing and we believe we can win.”

This was only the third day all season that the Mets were not in first place upon the completion of all scheduled games. On the other occasions, April 11 and Sept. 9, they moved back into first the very next day.

Saturday looked much the same as the opener Friday: Atlanta’s young frontline starter outpitched a Mets ace, Atlanta’s offensive firepower was far greater than the Mets’ lack thereof, and Atlanta’s bullpen was suffocating late.

“They’ve just played better than us. In every facet,” said Brandon Nimmo, who went 2-for-4 with a flyout to the wall in center. “They’ve done better pitching, they’ve done better hitting. They’ve hit those home runs against Jake and Max, and those are really the way you score runs against them [the two aces].”

Scherzer’s last start of the regular season was arguably his worst. He allowed four runs in 5 2⁄3 innings, and it could have been uglier.

“I’m fine with his outing tonight. He was solid. Never gave in and kept competing,” Showalter said.

Scherzer (11-5, 2.29) navigated three scoreless innings to begin the game by working around a bunch of hard contact. He wasn’t as fortunate in the next three.

Austin Riley doubled and Olson singled to begin the bottom of the fourth. The latter tied the score at 1.

After the Mets retook the lead in the top of the fifth on Jeff McNeil’s two-out RBI single, Scherzer gave it right back in the bottom half, yielding Dansby Swanson’s two-run homer to left-center to make it 3-2. Olson added a solo shot in the sixth.

“I left a fastball over the middle of the plate for Swanson to do damage with,” said Scherzer, who allowed four two-strike hits (of nine total). “That’s how you lose.”

Scherzer’s outing came with another historical footnote: His four strikeouts upped his career total to 3,193. He passed Fergie Jenkins (3,192) for 12th in MLB history.

The Mets had seven hits, all singles, and two runs off righthander Kyle Wright (21-5, 3.19), who lasted five innings. They loaded the bases with one out and forced Wright to throw 30 pitches in the first inning but managed only one run on Eduardo Escobar’s groundout.

Four Atlanta relievers combined for four shutout innings (and one hit). Dylan Lee, Jesse Chavez, trade-deadline addition Raisel Iglesias and Kenley Jansen each got a turn.

“When we’re not scoring runs,” Showalter said, “every little thing matters.”