BOSTON -- The Indiana Pacers walked away from Game 1's 133-128 overtime loss to the Boston Celtics knowing they missed an opportunity to steal home court to open the Eastern Conference finals Tuesday night.

With 22 turnovers, including two costly miscues in the final 27 seconds, the Pacers let victory slip away despite leading by three points with the ball in the final 10 seconds of regulation.

"We gave it away," Pacers forward Aaron Nesmith said. "We should've won the game."

The Pacers had a 3-point lead with 27.1 seconds remaining in regulation when guard Tyrese Haliburton dribbled the ball off his foot for an unforced turnover. Yet, Indiana got the ball back with a chance to seal the win at the free throw line with 10 seconds left.

The only issue was they had to inbound the ball. With 8.1 seconds remaining, an errant inbound pass from Andrew Nembhard to Pascal Siakam sailed out of bounds and gave Boston another chance to tie the score, which Jaylen Brown took advantage of with a 3-pointer in the corner.

"I think it's on us," Haliburton said. "They're a great defensive team, they got great defenders, individual and team defenders, but they're not a team who forces a ton of turnovers. I just felt like more of them were on us than them. We got to clean that up."

The Pacers also missed a chance to foul before Brown's tying 3-pointer, which Siakam said was his intention on the play, but Brown caught the ball in the corner with his shoulders squared to the basket and Siakam did not want to risk fouling a shooter and give up a four-point play.

The Pacers became the first team since at least 1997-98 to lose a playoff game despite inbounding the ball up 3 in the final 10 seconds, according to the Elias Sports Bureau.

Indiana's 22 turnovers were the second most it has committed all season and it contributed to 32 points for Boston, the most for the Celtics in any game this season.

"A lot of things had to go wrong for us and right for them," Pacers coach Rick Carlisle said.

Turning the ball over was uncharacteristic for Indiana, which entered the game committing the second fewest turnovers per game among playoff teams.

Over the final 5:30, including overtime, the Pacers had more turnovers (five) than field goals (two).

"We showed our age a little bit tonight," Pacers center Myles Turner said. "Being a youthful team and being in this high stakes of a game, those uncharacteristic mistakes just made their way out."

Despite missing a chance to win the opening game in this conference finals, the Pacers did not leave TD Garden hanging their heads. Boston raced to a 12-0 lead to begin the game and appeared ready to turn it into a rout. The Celtics maintained an advantage by double digits twice before the Pacers responded to take the lead on both occasions.

"All year long, our battle cry has been 'continue to play, continue to push tempo, continue to execute, keep playing no matter what,'" Carlisle said. "It's served us well and it did tonight too. So, we got -- it's unfortunate we did so many good things in this game that it came down to a couple of mistakes at the end. But, this is the NBA playoffs. And, we've got to learn from it, and we got to bounce back."

The Pacers have dropped Game 1 in each of the previous two rounds of the postseason and then gone on to win a long series. It left Haliburton encouraged despite the disappointment of losing in such fashion, especially when he considered how well they played on Tuesday night.

"We know we can play with these guys," he said. "We know we belong. It's discouraging just because of the plays that happened down the stretch, we felt like we were in position to win the game, just didn't win the game.

"But what I will say, is encouraging, we had been trash in Game 1s for the first series and second series. Today we played great for about 47 minutes, just didn't sustain for 48."

Game 2 is Thursday.