BOSTON (WISH) — The Pacers were up three points with 10 seconds left. They just needed to inbound the ball, get fouled and knock down free throws to ice the game. Andrew Nembhard struggled to get the ball in. Pascal Siakam couldn’t bring in the pass due to tight Celtics defense, and the ball went out of bounds, off of Siakam.

The Celtics took advantage.

Jaylen Brown got the inbound pass in the corner for Boston on its next possession and drained a three with six seconds left to tie the game and sent it to overtime.

The Celtics would win it in the extra five minutes, 133-128. With the victory, Boston takes a 1-0 series lead in the Eastern Conference Finals.

“This loss is totally on me,” Pacers head coach Rick Carlisle said. “With 10 seconds in regulation we should have just taken the time out, advanced the ball, and found a way to get it in and made a free throw or two and ended the game.”

The Pacers had a lead late in overtime as well, leading by two points with 1:12 remaining. Then, Jayson Tatum powered through T.J. McConnell for an and-one layup. On the next possession, he hit the dagger on a smooth slide-step three-pointer to put the Celtics up four.

“Of course it’s frustrating,” Pacers guard Tyrese Haliburton said. “We felt like we were in position to win the game. But, you can’t dwell on it. What I will say, we’ve lost every Game 1 but we’ve responded well in all these Game 2s. So I expect that from this group. I expect us to be ready to go.”

It wasn’t always the Pacers game to lose though. The Celtics came out of the gates hot, starting on a 12-0 run. It looked like nothing was going to go right for the Pacers. But, they chipped away at the lead for the rest of the first half and had it tied up at halftime.

Turnovers were an issue for the Pacers. They had 21 of them and Haliburton had two late turnovers, which hurt Indiana in big moments.

“More of them (turnovers) were probably on us than them forcing them,” Haliburton said. “So we got to clean that up.”

Seven Pacers hit double figures in points, including all five of their starters. Haliburton lead the charge with 25 points and knocked down six three-pointers. Two of them came in the last three seconds of the quarter, as he hit a three from the logo at the end of the second quarter and a buzzer-beater three off the glass to end the third quarter.

Jayson Tatum led the Celtics with 36 points. All five of their starters hit double figures in scoring as well.

The Pacers will look to even up the series on Thursday at 8 p.m.