Jerry Seinfeld’s stunned reaction, Taylor Swift’s constant cheering for Ben Stiller, Fat Joe, and Timothée Chalamet’s energy were the reasons why the Knicks were able to complete the largest comeback in NBA Finals history. The San Antonio Spurs led by 29 points, but it was not enough to stop the New York barrage in the second half. But former tennis star and ESPN analyst John McEnroe almost missed the Miracle at Madison Square Garden, as his friend and fellow celebrity Knicks fan Larry David insisted on leaving.

“We were sort of a little negative at 71-42,” McEnroe told the ESPN crew on “NBA Today” on Thursday. “He was like, ‘Let’s get outta here.’ He was like, ‘Let’s get outta here.’ I go, ‘Larry, listen, over the years it hasn’t come up the way we expected [as Knicks fans].’ You know, I’ve blown a couple [of] big leads in my life….It was sort of like, ‘Here we go again, we’re gonna lose this. Something bad’s gonna happen.’”

But McEnroe said he tried to get David to be a bit more positive in the face of an uphill battle for the Knicks. “I said, ‘Larry, let’s get positive here. If they get it down [from 29] to 25, 21, 18, it’s 15 at the end of the [third] quarter.’ This type of stuff. ‘Let’s keep it positive,’” McEnroe continued. “That’s the most positive I’ve ever been at a game, and I’ve been at a lot of sporting events over the course of my 56 years of coming to Knicks games when I was 8 years old.”

David stayed, and the pair witnessed the Knicks storm back with a 58-30 second-half run. Spearheaded by Jalen Brunson’s 36 points and sealed by a late OG Anunoby tip-in, New York won 107-106. The stunning victory gave the Knicks a 3-1 series lead. The celebrity row lost its mind after the final horn.

Taylor Swift was seen swinging a towel and dancing with Knicks fans while exiting the world’s most famous arena. Mariska Hargitay, the Law & Order: Special Victims Unit actress, even compared the moment to her wedding.

“I love my husband, and our wedding night was great and all, but I think it might have been the greatest night of my life,” Hargitay told The Hollywood Reporter. The comeback also sparked a viral moment where a stressed Larry David nearly collapsed onto McEnroe after a late-game missed layup.

Larry David gave another epic moment during the Knicks’ comeback

With 1:47 left in the game, Knicks forward Josh Hart picked up a loose ball and had a breakaway for a dunk to give his team its first lead of the game. Lo and behold, he missed it, and the “Curb Your Enthusiasm” star had an epic reaction. David, like the entire standing MSG, was standing up, cheering on in the final few plays. He was next to McEnroe and Warner Bros. Discovery CEO David Zaslav, and as he watched the miss would tightly grab onto both men like he was going to collapse right there on the floor. Thankfully for the Knicks fans, the moment won’t haunt them as Anunoby came in clutch.

“I’ve got a special shoutout for OG, man, because he saved me, at least for this game, a lifetime of regret,” Hart said after the game.

Even the “Seinfeld” co-creator spoke to the Post’s Mike Vaccaro on Thursday, still trying to process what he saw in the second half.

“It was hard for me to believe that I — and I would italicize the ‘I’ if I knew how — that I could witness that,” David said. “I’m supposed to miss games and moments like that. That’s what I was thinking.”

David agreed that he was supposed to miss games like this. And he nearly did. But John McEnroe talked him out of it. Now, Game 5 is scheduled for Saturday at the Frost Bank Center in San Antonio, where the Knicks can win the championship for the first time since 1973.