NEW YORK -- Gervonta Davis wasn't letting his hands go, and Rolando Romero took advantage. He stalked "Tank" Davis and even forced him to hold on at times after he connected with a couple of power shots.

But, as he always does, Davis found a way with his devastating left hand, a counter shot that sent Romero crashing face first on the rope. "Rolly" beat the count on unsteady legs, and the referee stopped the bout, giving Davis yet another brutal TKO victory on Saturday in a career filled with them.

The end came with 21 seconds remaining in Round 6 before 18,970 at a sold-out Barclays Center, allowing Davis to retain his WBA "regular" lightweight title and perhaps move on to a high-stakes showdown with Ryan Garcia, who was ringside.

"He was strong for sure but it was a couple shots that I was getting warmed up and he caught me and I was like, 'I can't sit with him just yet,'" said Davis, who was ahead on two scorecards 49-46 and 48-47, while Romero was ahead on the other 48-47.

"I know when to take it to my opponents and when to chill out. There was someone in the crowd ... and they were telling me to press forward and I was like, 'Not yet, I got to loosen him up a little more.'"

Shortly after Davis left the ring Saturday night, many fans attempting to depart Barclays Center ran back in toward the arena floor, some even leaping up into the ring in panic.

A Barclays Center security supervisor told ESPN there was a person with a gun in the outdoor main plaza that led to the stampede of fans who rushed back into the arena. Multiple people were transported to a local hospital, the official said, who estimated approximately a dozen injuries. Among them: a concussion and an elbow injury.

An NYPD detective told ESPN they were looking into the possibility there was a shooting. Tennis star Naomi Osaka, who had been ringside, tweeted, "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. I was so f---ing petrified."

Security held some fans in one area for a time as the situation was addressed. It was unclear in the immediate aftermath whether it was directly connected to the boxing match.

Davis (27-0, 25 KOs) was set to fight Romero in December, but Romero was pulled from the fight after he was accused of sexual assault. Instead, Davis struggled to a decision over Isaac Cruz, his first distance fight since 2014.

In the meantime, no charges were filed against Romero, and the heated promotion that started in October kicked back into high gear as the underdog attempted to antagonize Davis. When the bell finally rang on the bout months in the making, Romero, known for his awkward, free-swinging style, employed a more focused, disciplined strategy.

He doubled and tripled up on the jab and effectively kept the smaller Davis at bay. On multiple occasions -- particularly in Rounds 2, 3 and 5 -- Romero connected with punches that caught Davis' attention. There was never any doubt Romero could punch. But in his first legitimate test, the question was whether he could box soundly round after round against one of the sport's elite fighters and prove he can absorb a punch.

"The crazy thing is I didn't even throw it that hard," said Davis, who has also competed at 130 pounds and 140. "I just threw it. He just ran right into it. Something like when [Manny] Pacquiao got caught by [Juan Manuel Marquez]."

Romero (14-1, 12 KOs) acknowledged that he erred when he "jumped into his shot" but felt he was in control otherwise. The 26-year-old from Las Vegas said Davis was hurt on multiple occasions, particularly from a stiff jab, and felt he won every round until the finish.

"He caught me with a left hook," Romero said. "I'm a warrior, I wanted to continue to fight. ... I won every moment of that fight. I exposed him and we need to run that s--- back. ... I had him running ... the entire fight. He got a nice shot in. He was scared of me. He won't fight me again."

A rematch, of course, isn't an appetizing option. What is: A Davis fight against the likes of Garcia, Devin Haney or George Kambosos, the undisputed lightweight champion who fights Haney next weekend.

"Golden Boy is not going to put" Garcia anywhere near Davis, said Mayweather Promotions CEO Leonard Ellerbe, who promotes both Davis and Romero. "The closest he's going to get to Gervonta Davis is where he was tonight. He don't want to fight 'Tank.' It's all talk. All talk."

No matter whom Davis fights next, there's no doubting his star appeal. The Baltimore native brings the stars out time and time again, and packs houses all over the U.S. Atlanta. Los Angeles. And now Brooklyn. Madonna was ringside. So were Michael Strahan and Tracy Morgan.

Davis is clearly among the biggest stars in all of boxing. Now he just needs a high-level dance partner to reach the next level and inch closer to his mentor, Floyd Mayweather.

Information from The Associated Press was used in this report.