NEW YORK -- For a few moments, it appeared as though the Brooklyn Nets had won the summer free-agency sweepstakes but were destined to lose their first matchup with their crosstown opponents.

Then, Kyrie Irving, who has made a name for himself as a premier shooter under pressure, sank a go-ahead 3-pointer as the clocked ticked down to 21 seconds left in Friday's fourth quarter. The Nets, once up by 19, were able to hang on to beat the Knicks 113-109.

Afterward, Irving spoke about the difference in the rivalry with the Knicks since the Nets moved from New Jersey to Brooklyn.

"That was more a subway rivalry back when they played in New Jersey," Irving said. "Now that they're in Brooklyn, it's like a battle for who runs New York City."

Although it was only the second game of the regular season for each team, the matchup had been keyed up as a high-stakes rivalry.

The New York glitterati came out in droves to take in the clash of the boroughs. Spike Lee, a die-hard Knicks fan, traveled across the bridge to watch the game courtside in Barclays Center. Yankees right fielder Aaron Judge was in attendance, as was pitcher CC Sabathia. Early attendance had been sweetened by the promise of a free Irving jersey to the first 10,000 fans to arrive for Friday night's game. Two hours before tipoff, a line of fans stretched down the block from the entrance of Barclays Center to the corner of Atlantic Avenue.

Once inside, the crowd was electric.

"Just having everything thrown in the Knicks' face like, 'Kyrie is on our team -- ha-ha-ha,'" Nets center Jarrett Allen said after the game. "I think it did have a little weight on their side, plus we got the win, too. They [are] going to be hungry next game."

From opening tip, Nets fans' chants gloated about the team's summer acquisitions, but Knicks fans squawked loudly after each made New York bucket. Section 114, nicknamed the "The Block," bobbled between "We got KD and Kyrie, you got Dolan" chants and "Where is Zion?" in reference to the Knicks missing out on selecting No. 1 overall in the 2019 NBA draft (where the New Orleans Pelicans picked Zion Williamson).

The game unfolding below the screaming fans was bumpy. In total, the two teams combined for 57 personal fouls -- 31 by the Knicks and 26 by the Nets. At one point, the Nets' Taurean Prince and the Knicks' Bobby Portis were issued technical fouls after diving for a loose ball led to a scuffle. Security guards had to rush off the bench to ensure the kerfuffle didn't escalate. Each team also committed 26 turnovers.

"There were a lot of mental mistakes," Nets coach Kenny Atkinson said after the game. "A lot of silly fouls. A lot of general breakdowns that almost cost us. Even though we won the game, we will have another long film session to look at all the mistakes we made. We made a lot."

The Nets led by 11 points heading into the final quarter, but a quick 3-pointer from the Knicks prompted Atkinson to call for a timeout. By the six-minute mark, the Nets' double-digit lead had diminished to just six points. The crowd ebbed and flowed with each basket. When the Nets took the lead, Brooklyn fans roared and banged on their chests. When the Knicks surged back ahead, Barclays Center sounded like an extension of Madison Square Garden. Then it was back to a Nets home-crowd advantage when Irving hit an improbable floater.

Almost every fan in the arena was standing for the final play of the game. As cameras panned around the arena, searching for shots of Nets fans hollering, it was impossible to zoom in on a frame that didn't include orange-and-blue sweatshirts and hats.

In the final 3 minutes and 41 seconds, the Nets went on a game-sealing 7-0 run. In the Knicks' final seven possessions, RJ Barrett missed a field goal, Wayne Ellington's 3-point attempt clanked off the rim and Julius Randle missed a layup. Ellington traveled, Marcus Morris missed, Randle turned the ball over and Irving stole the ball from Ellington.

Then Irving hit a dagger, sealing the Nets' first victory of the Irving era.

"It's the same shot he hit to win the championship against Golden State," Barrett said. "It's tough. I was right there. There's nothing else that you can do about that."

Irving, who scored 50 points in the Nets' opening-night loss to the Timberwolves, set a record for the most points (76) scored by a Nets player in the first two games of a season, according to Elias Sports Bureau research.

As Irving and his teammates made their way back to the locker room, Nets fans streamed toward the exits, singing "Brooklyn's better" before disappearing out the doors of Barclays Center and into the chilly October air. Even if it was just for one night, Nets fans could claim they run the city.