Knicks fans were partying like it’s 1999.

After the Knicks defeated the Cavaliers 99-79 in a blowout victory in Game 3 at Madison Square Garden on Friday night, fans were reveling in the streets of Manhattan.

In one particularly surreal scene, a one-on-one basketball game broke out between two Knicks fans on Eighth Avenue, with a basketball hoop affixed to the top of a school bus.

WFAN personality Craig Carton shared a video in which a horde of fans was chanting, “Let’s Go Knicks!” at the corner of West 31st Street and Seventh Avenue.

At the same corner, a video emerged of a man climbing the street sign as an onlooker yelled excitedly, “We’re gonna have to be like Philly and start greasing poles!”

Meanwhile, another video showed what appeared to be hundreds of Knicks fans boisterously chanting, “Knicks in Five! Knicks in Five!”

In a video that has been viewed close to two million times on Twitter as of late Saturday morning, a Knicks fan yelled to “Show KD!” a video of the reveling scene, referring to Kevin Durant, who along with Kyrie Irving chose to sign with the Nets over the Knicks in 2019.

Durant and Irving have both since left the Nets’ organization via trade.

Irving went to the Mavericks, who flamed out of the playoff picture and Durant’s Suns appear primed to advance to the second round of the NBA playoffs with a 2-1 lead over the Clippers and Los Angeles star Kawhi Leonard out for at least Game 4 with a knee injury.

The Knicks are favored by two-and-a-half points at home over the Cavs in Game 4 on Sunday afternoon and are -200 favorites — meaning bet $200 to win $100 — to advance to the second round, where they would play the winner of the series between the Bucks and Heat.