BOSTON — Year after year, NBA executives vote Rick Carlisle one of the league’s best in-game coaches.

Carlisle, the Indiana Pacers’ head coach, admitted late Tuesday night he didn’t have his finest moment in the final seconds of regulation in the Boston Celtics’ 133-128 overtime victory against the Pacers in Game 1 of the Eastern Conference finals.

“This loss is totally on me,” Carlisle said.

The Pacers had a 117-114 lead and the possession of the basketball but turned the ball over on the in-bound pass, leading to Celtics guard Jaylen Brown’s overtime-forcing corner 3-pointer with 6.1 seconds left in the fourth quarter.

“With 10 seconds (left) in regulation, we should’ve just taken the timeout, advanced the ball, and found a way to get it in and made a free throw or two and ended the game,” Carlisle said. “It didn’t happen.”

Unlike many Pacers players who are playing in the conference finals for the first time, Carlisle is a championship coach with decades of experience.

He wasn’t the only one making mistakes in a game the Pacers will look back on as one should have won. Indiana committed 22 turnovers that led to 32 points. Beside the aforementioned late-game turnover, Pacers All-Star point guard Tyrese Haliburton lost the basketball out of bounds with 27.7 seconds left in the fourth quarter with the Pacers ahead by three points, and Haliburton had another one in overtime, leading to a Jayson Tatum 3-pointer that put the Celtics up 127-123.

“We made mistakes, so that’s an area we need to clean up,” Carlisle said.

Even Brown’s 3-pointer that sent the game to overtime is under scrutiny. Up three, why not foul and prevent a game-tying 3? That was the instruction. However, Brown caught the ball in the corner ready to shoot, and Pacers forward Pascal Siakam didn’t want to risk fouling Brown and giving him the chance at three free throws or a four-point play.

“He caught the ball and was face up, and Pascal decided to lay off which I understand was probably the right decision,” Carlisle said.

Said Siakam: “As soon as I got to him – I was a little late because of the screen – he was going up so I didn’t to do it (foul). I was a little too late. If you have an opportunity to do it, you do it. I felt like he was going into his (shooting) motion. It was a tough shot. Maybe I could’ve contested it better. It was just a tough play.”

The image of Siakam with his hands behind his back and Brown launching a 3 in front of the Pacers’ bench will haunt Indiana. At least until Game 2.

“A lot of things had to go wrong for us and right for them. They did,” Carlisle said. “We’ve got to own it and we’ve got to get ready for Thursday.”

The Pacers played well enough to win. They shot better from the field (53.5%-47.5%) and 3-point range (37.1%-33.3%), outrebounded Boston, had more assists and Indiana’s bench outscored Boston’s 30-13.

But those turnovers and refusal to call a timeout cost Indiana. Those plays not only sway a game, they have the potential to sway a series. The sixth seed can’t waste many opportunities against the one seed.

“We’ve been a tough-minded, resilient team the second half of the year,” Carlisle said, “and we’ve got to continue that.”