Jaylen Brown hailed the Boston Celtics' never-say-die attitude after his last-gasp 3-pointer teed up their overtime win in Game 1 of the Eastern Conference finals.

The Indiana Pacers were just 6.1 seconds away from a 117-114 road win in the opening game of the series on Tuesday, only for Brown to sink a 3 over Pascal Siakam from the corner to level things up.

Two Tyrese Haliburton free throws put the Pacers back in front in overtime, but Jayson Tatum scored 10 of his game-high 36 points in the additional period as Boston triumphed 133-128.

Jrue Holiday supported Tatum with 28 points, while Brown added 26. All three players finished with three steals apiece as Indiana committed 21 turnovers.

Speaking after the dramatic finale, Brown said: "Welcome to the NBA playoffs! You've just got to manage your emotions. Anything can happen. 

"It's not over until the final buzzer sounds. It's not over until it’s over. We found a way to win the game at the very end."

Holiday echoed those sentiments, adding: "We've seen crazy stuff happen all the time. 

"We don't think we've lost a game until we've actually lost the game. That's part of the reason why we were so resilient towards the end.

"A couple of turnovers, a great shot, a great look by JB, or at the other end if we make a couple other shots that were wide open it could be a completely different game. 

"We're just the type of team that's going to keep on fighting no matter how long and no matter what it takes."

The Celtics host Game 2 on Thursday as they target a first NBA Finals appearance since 2021-22, when they were runners-up to the Golden State Warriors.

Asked how Boston will approach Game 2, Tatum said: "Don't relax, it'll be different circumstances. The first two rounds we won our Game 1 by a wide margin, so maybe human nature played into that. 

"But tonight being a close game, going into overtime, we certainly felt like we should have won and we could have played better."