Boston Celtics beat the Brooklyn Nets 115-114 at the buzzer in their first NBA playoff game.

The Eastern Conference second seeds held off a fourth-quarter comeback by the Nets thanks to Jayson Tatum’s 31 points.

In the best-of-seven first-round series, the Celtics are up 1-0.

During the third quarter, Kyrie Irving, who scored 39 points for the Nets against his former team, lifted his middle finger to the Boston audience.

Irving has had a strained connection with the Celtics’ supporters since his contentious departure in 2019, who booed him throughout the game.

“I’m used to all of this,” Irving, 30, added.

“When I come into this building, it’s nothing new in terms of what it’s going to be like – but it’s the same energy they have for me, and I’m going to have the same energy for them.”

The defending champion Milwaukee Bucks, Miami Heat, and Phoenix Suns all won their first games.

The Milwaukee Bucks defeated the Chicago Bulls 93-86, led by Giannis Antetokounmpo, one of three finalists for the NBA’s Most Valuable Player award this season.

The Heat, who are the top seeds in the Eastern Conference, upset the Atlanta Hawks 115-91, while the Suns, who are the top seeds in the Western Conference, defeated the New Orleans Pelicans 110-99.

Thanks to a three-pointer by Irving, the Celtics trailed the Nets 114-111 with 45.9 seconds left in Boston.

Celtics supporters booed Irving, who led the Nets with 39 points, and he threw them a middle-finger gesture in the third quarter.

However, a Jaylen Brown layup cut the margin to one, and after Kevin Durant missed a three-pointer, Tatum scored the game-winning basket on a Marcus Smart assist.

“We just kind of made eye contact when he took that dribble and he made a nice pass and I just had to hit a layup,” Tatum said.

Irving, on the other hand, defended his reaction to the Celtics’ supporters.

“It’s nothing new when I walk into this place in terms of what it’ll be like,” he added, “but it’s the same energy they had for me, and I’m going to have the same energy for them.”

The seven-time NBA All-Star, though, stressed that the contest’s focus should not be on his fan connection.

He stated, “It’s not about the fans.”

“The fans aren’t interested.”