Jets quarterback Sam Darnold celebrates after defeating the Dallas Cowboys at...

Jets quarterback Sam Darnold celebrates after defeating the Dallas Cowboys at MetLife Stadium on Sunday. Credit: Lee S. Weissman/Lee S. Weissman

It took only a few seconds for Sam Darnold to realize this was going to be a good day. A very good day.

The first time he touched the football in a game in more than a month, he knew.

Darnold heard the play call in his headset from coach Adam Gase, walked up to the line of scrimmage and awaited the snap from center Ryan Kalil.

“I knew the coverage right away,” he said a few minutes after the Jets’ 24-22 win over the Cowboys at MetLife Stadium on Sunday. “Right when I whipped my head around [after faking a handoff to Le’Veon Bell], I knew what to do with the ball.”

Darnold saw Demaryius Thomas streaking across the middle of the field and delivered a perfect strike that Thomas caught in stride, good for a 17-yard completion.

“That pass I made to DT, I knew we were going to have a good game offensively,” Darnold said. “It was that kind of a day.”

He had missed the previous three games while recovering from mononucleosis, and the Jets were a complete mess without him. They lost to the Browns, the Patriots and the Eagles. After backup Trevor Siemian suffered a fractured ankle against the Browns, poor Luke Falk didn’t stand a chance. He didn’t belong on an NFL field, and the Jets’ 0-4 start was a testament to that reality.

Darnold’s return made all the difference in the world, and his play reflected it. He went 23-for-32 for 338 yards, two touchdowns and an interception for a 113.8 rating, plenty good enough for the Jets to jump-start their season and give them a chance of being relevant at the very least.

And playoff-worthy at the very best.

It’s still a long way from here to the tournament, and history is very much against teams that start off 0-4. But the Jets now have a functional offense with Darnold’s return, and the entire team fed off No. 14 being back under center.

“He did a damn good job,” said safety Jamal Adams, who ensured the victory with his blitz up the middle on the Cowboys’ potential tying two-point conversion in the final minute. “We have a lot of faith in Sam. He wasn’t drafted in the top five for no reason. He’s a hell of a leader, a hell of a competitor.”

And a hell of a thrower.

Darnold was on target through most of the game, with one glaring exception, and made a throw that ignited the victory.

After Adams and Quinnen Williams stopped quarterback Dak Prescott on fourth-and-2 from the Jets’ 7, Gase called for a deep throw to speedy wide receiver Robby Anderson. Darnold hoisted the ball skyward and Anderson got under it near midfield. He wasn’t touched the rest of the way, going 92 yards for the second-longest offensive touchdown in franchise history.

Boom.

“The way the safety bit down on the run, I just knew I had to put it out there,” Darnold said.

The momentum swing of the fourth-down stop and the touchdown were pivotal moments in the game. And maybe the season.

“To win the way we had to win it .  .  . all the little things that had to happen in the fourth quarter, that’s the way we had to win,” said Gase, who got his first win as Jets coach. “Our guys needed that.”

Darnold was the biggest part of that win, although he wasn’t without fault and helped keep the Cowboys in the game. He misfired on a pass to Jamison Crowder and the ball was picked off by cornerback Jourdan Lewis at the Cowboys’ 6.

The Jets were up 21-9 at the time and were fortunate that Cowboys kicker Brett Maher missed a 40-yard field-goal attempt on the next possession. Darnold knows he could have all but put the game away there.

“Bad read on my part,” he said. “I just made a really bad throw and a really bad read.”

Darnold had hoped to return last week against the Eagles, but his spleen hadn’t returned to its normal size when he was examined two days before the game. Gase had been heavily criticized for giving Darnold all the first-team reps during that week, which left Falk less prepared than he might have been. But Darnold believes he benefited from the extra work.

“I definitely think the two weeks of practice helped,” he said. “It hurt Luke, but looking back on it, it helped me for this game [against Dallas].’’

And that was a gamble worth taking for Gase, who wouldn’t have had a shot against the Eagles even if Falk had gotten every first-team rep during the week.

Better to have Darnold ready for this one — when the Jets earned their first win of the season and, more importantly, reclaimed hope.

Newsday LogoSUBSCRIBEUnlimited Digital AccessOnly 25¢for 5 months
ACT NOWSALE ENDS SOON | CANCEL ANYTIME