NEW YORK – The countdown begins in the first inning, with a bullpen acutely aware of the challenge ahead.

“How,” Drew Smith wondered, “can we get 27 zeros?”

Navigating 27 outs in a postseason game is always a bear. It can be overwhelming to do it against this ruthless Los Angeles Dodgers lineup, the one that doesn’t swing on pitches outside the zone.

Do you do it with a tired and ineffective bullpen? Sisyphus sympathizes with you.

And yet here were the New York Mets, late Friday night, their bags packed and their buses leaving for the airport and another cross-country flight to Los Angeles. The Mets extended their season with a 12-6 victory over the Dodgers, which felt more exciting than the margin. Game 6 of this National League Championship Series is scheduled for Sunday evening in Chavez Ravine.

“This is something we’ve been doing all year,” starter David Peterson said. “We’re going down, and we’re going to keep showing up and competing.”

In the aftermath of Thursday night’s Game 4, Ryne Stanek and Edwin Díaz walked back together from the bullpen, neither used in another lopsided loss. The Mets had used everyone else in that pen for more than three outs the last two nights. They could do the math.

“We joked, ‘You got two (innings) and I got two,’” Stanek said. “So we were really anticipating it.”

It turns out they underestimated it.

Because with 13 outs left in a 10-5 game, Carlos Mendoza pulled Reed Garrett. He went to Stanek in the fifth inning to face Shohei Ohtani, and Stanek knew there was no one but Díaz behind him.

Last week, Stanek had passionately pointed out an overlooked aspect of Sean Manaea’s Game 3 victory over the Phillies in the NLDS. Manaea had induced a huge double play to end the sixth inning, which felt like it could be the end of his outing. Instead, he came back for the seventh and eighth to save New York’s bullpen.

“I don’t know if the fans at home or in the stands will appreciate that enough,” he said. “It’s so hard to have that emotional release and go back and still control yourself.

‘It’s hard to ask him to do more – and he has. That was great. That’s the s- that turns me on.

It’s exactly what Stanek did on Friday.

On 31 pitches, Ryne Stanek delivered 2 1/3 innings from the bullpen. (Sarah Stier/Getty Images)

The 33-year-old pitched eight seasons in the big league. Friday marked his 430th Major League appearance; it is the first time he has ever received a seventh clean sheet in a match. He had only been asked to pitch three innings once before, as a rookie in 2017. (That time, he allowed the only three batters he faced in that third inning to reach range.)

But he retired Ohtani in the fifth, recovered from a Mookie Betts solo home run in the sixth and retired the side in the seventh. When Gavin Lux threw his 31st pitch, he didn’t wait for Jeff McNeil to catch it before he started barking his way to the dugout – finally ready for that emotional release.

“It’s a cool feeling,” he said Friday. “Knowing the course isn’t one out, two or four, you try to hold yourself back from that lull. You try to keep as even a keel as possible and let it sail.

“He’s great,” Brandon Nimmo said. “It’s what we ask of everyone: to go beyond where they’ve been and be able to deliver results. He did it and then some.”

From then on it was Díaz’s turn. He had walked to the bullpen an inning early and started stretching an inning early. He threw his first warm-up pitch in the seventh with Stanek in the game. Going into the eighth, he knew the last six outs were his and there was no backup in the pen.

The closest retired six of the seven Dodgers he faced as sharply as he was this month, needing just 23 pitches to do so.

“We definitely needed everyone,” Smith said. “You’ll get them any way you can.”

The Mets were able to count all the way to 27 zeros on Friday. Now all they have to do is count to two more wins.

“We haven’t done anything easy yet this year,” Stanek said. “Why stop now?

“We can beat them,” Díaz said. ‘We’re going to Manaea on Sunday. We can beat them.”

(Top photo of Edwin Díaz and Francisco Alvarez: Al Bello / Getty Images)