Video posted online shows crowds fleeing in terror as panic swept through Barclays Center over a false report of a shooting early Sunday, leaving more than a dozen people injured.

Tennis star Noami Osaka was one of those caught up in the mayhem in the Brooklyn area as the NYPD said seven of those injured were hospitalized.

Footage, including at least one clip posted on TikTok, showed a frantic stampede, with people ducking and running inside the arena that had hosted the Gervonta Davis-Rolando Romero boxing match earlier that night.

Osaka said she was “petrified” when she was forced to huddle in a room while the chaos broke out.

“I was just in the Barclays center and suddenly I heard shouting and saw people running, then we were being yelled at that there was an active shooter and we had to huddle in a room and close the doors,” Osaka said on Twitter.

In a follow-up tweet, the four-time tennis Grand Slam champion said: “I really hope everyone made it out safely, since I’m tweeting this we made it out ok.”

Boxing reporter Ryan Songalia previously told The Post that only media and production workers were still in the Barclays when a fight broke out and some mistook the commotion for a shooter.

The NYPD said no gunfire went off, though there was a fight not far on Atlantic Avenue and Fort Greene Place at around 1 a.m. involving a man who then ran toward the Atlantic Terminal mall.

Crowds then started running in the same direction, contributing to the confusion, cops said.

Investigators have video of the incident and it is being investigated, a police source told The Post.  

The frightening scene came less than a week after a twisted mass shooter killed 21 people, including 19 students, inside Robb Elementary School in Uvalde, and about two weeks after ten people were fatally shot inside a grocery store in Buffalo by another mass shooter.

“We’re used to brawls at boxing events but recent headlines and the panic of the crowd made many of us worried that our worst fears would come true,” Songalia said. “Thankfully we were able to return to our seats to file our stories and exit safely.”