Knicks fans celebrate a 38-point drubbing of the Boston Celtics in Game 6 at MSG to reach the Eastern Conference finals for the first time in 25 years. Credit: Ed Quinn

It was like New Year’s Eve in Times Square, only warmer, a few blocks south and with a climax that arrived before midnight.

And, perhaps most importantly, this: Unlike New Year’s, this was no annual event.

The Knicks had just routed the Celtics, 119-81, on Friday night at Madison Square Garden to advance to the Eastern Conference final for the first time since 2000.

And it was the first time they had clinched any playoff series at home since 1999.

So there was a lot to revel in.

When it was over, fans from inside the arena, from the similarly filled-to-capacity watch party on 33rd Street and from area taverns converged on Seventh Avenue.

Terrell Smith Credit: Newsday/Neil Best

Soon police barricades were strewn on the ground and the major traffic corridor outside the Garden became a chaotic, celebratory pedestrian mall.

“This right here is bananas!” Terrell Smith of Brooklyn said. “Amazing. It’s exciting. New York in the house!” She added, “Hello, Melo! Orange and blue skies!”

Smith said she had been a “New York Knickerbocker fan forever, ever, ever. Win, lose or draw. I’ve been a New York Knickerbocker fan since I was born – 1971!”

Most of the fans partying like it was 1999 were younger than that, but the crowd was a multi-generational, multi-ethnic, multi-gender lovefest full of strangers high-fiving and hugging.

Smith had been inside the arena, but Will Decker, James Decker and David Morrison could not even squeeze into the watch party, so they settled for a nearby bar.

That did not dampen their enjoyment.

From left, David Morrison, James Decker, Will Decker celebrate after...

From left, David Morrison, James Decker, Will Decker celebrate after the Knicks won Game 6 at MSG against the Celtics on Friday. Credit: Newsday/Neil Best

“This is awesome, dude,” said Will Decker, 35, from Rockland County. “It’s the experience of a lifetime.” 

Said his brother, James, “It’s an unreal feeling as a fan. We’ve been wanting this for so long that it doesn’t even feel real right now. It’s a surreal feeling to be here.

“We’re so blessed with [Jalen] Brunson and this crew. These guys know how to get it done.”

David Morrison, 32, of New Jersey said his first memory is of Larry Johnson’s four-point play against the Pacers in the 1999 playoffs, and of watching it on a “big-[expletive] CRT TV.”

Now we are deep into a new century and a new Knicks era, one in a social media age rather than one captured on cathode-ray tubes.

Many fans outside the Garden took still pictures and videos of one another, including those who climbed street sign poles and the taxi stand on Eighth Avenue.

At least one man intentionally jumped off the top of the taxi stand into a crowd. But at Seventh Avenue and 33rd Street, a man hanging on a traffic light pole accidentally lost his grip and fell to the ground.

Fans cheered when he arose, seemingly unhurt.

The crowd mounted obscene chants aimed at the Celtics, the Pacers and even the Hawks’ Trae Young, whom the Knicks will not see in these playoffs. But mostly it was happy songs, including multiple rounds of “Go, New York, go New York, go!”

Remember: This only was the end of the second round. What might Seventh Avenue look like four or eight victories from now?

“We’re not done yet,” Sean Semple of Brooklyn said. “It is going to extend to the East River if we win a championship.

“I don’t think you can imagine what it would be like, honestly.”

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