It was controversy and chaos with LeBron James and the Lakers in town, but the Celtics eked out a win in OT

Grant Williams (left) rushes over to celebrate in overtime with Jaylen Brown, who scored 11 points in the extra time and 37 overall.Barry Chin/Globe Staff

After Jaylen Brown missed two free throws late in overtime of the Celtics’ loss to the Knicks on Thursday, the end of a forgettable night for him, he said he had let his team down. He vowed to be better next time, and the good thing about the NBA is that next time always arrives suddenly.

On Saturday night, with the Celtics on the ropes against the Lakers, Brown soared in for an offensive rebound and scored as he was fouled, pulling Boston within one with 4.1 seconds left. He once again stepped to the free-throw line, where once again a miss would probably have cost his team the game.

But this time, his mind was not racing. This time, time stood still.

“No doubt in my mind,” Brown said later.

He made the free throw to force overtime, then erupted for 11 of his team-high 37 points in the extra session, sending the Celtics to a 125-121 win and snapping their three-game losing streak.

“I’m just happy for him,” Celtics coach Joe Mazzulla said of Brown. “The league gives you opportunities to constantly bounce back, and he’s really got a great mindset.”

The end of regulation was filled with controversy and chaos, however, and the officials later admitted to missing a critical call that would have given Lakers star LeBron James a chance to win the game.

After Brown’s game-tying free throw, James lowered his head and attacked the basket. As he missed a layup with a half-second left, Celtics forward Jayson Tatum appeared to make extensive contact with James’s arm, but no foul was called.

James was furious and stunned. He slapped his arm to mimic the foul, jumped up and down and put his hands on his head. But it did no good at that point.

Then Lakers guard Patrick Beverley, who had positioned himself to be the Lakers’ hero after drilling a 3-pointer and throwing down a powerful follow-slam in the final 52 seconds, walked onto the court with a camera and appeared to show a referee a picture of the foul they had not called. He was whistled for a technical foul before overtime began, giving Boston a rare one-point lead at the start of the extra session.

In a pool interview after the game, crew chief Eric Lewis acknowledged the officials’ mistake.

“There was contact,” Lewis said of James’s shot. “At the time, during the game, we did not see a foul. The crew missed the play.”

While it was an honest admission, it did not change the result, and certainly did nothing to soothe the Lakers.

“He fouled him,” forward Anthony Davis said. “He fouled him. Clearly. Clearly. It’s [expletive]. But at the end of the day, like, it’s unacceptable. And I guarantee nothing is going to happen to the refs. We got cheated tonight, honestly. It’s a blatant foul.”

When Tatum was asked about the play afterward, he held back a smile and sheepishly did the basketball equivalent of pleading the fifth.

“The last two minutes and overtime were a blur,” he said. “I don’t really know what happened. Think I have to watch the game, watch the film. Everything happened so fast. Got to move on and we got the win. That’s all I got to say about that.”

Malcolm Brogdon (front) can only watch as the Lakers' LeBron James splits the defense of Jaylen Brown (left) and Grant Williams.Barry Chin/Globe Staff

The fortuitous ending certainly made it easier for Tatum to shake off a rare off night. He had 30 points but made just eight of 25 shots and added six turnovers. He played the final 41 minutes of the game and 47 total, and after tussling in another overtime matchup just two days earlier, he said he was exhausted after this one.

But thanks to early foul trouble Brown played just 38 minutes, and that unplanned rest ended up being helpful later, as he punished the Lakers with his powerful closing kick.

“You can just tell that he wants to be great and we trust him in those moments,” Celtics guard Derrick White said. “He came up a little short [against the Knicks], but we trusted him again tonight, and he did what he did.”

The Celtics led, 100-99, before Beverley hit a 3-pointer from the right arc with 50.6 seconds left in regulation. Malcolm Brogdon (26 points) responded with two free throws to tie the score at 102.

Davis then missed a 3-pointer from the right corner, but the 6-foot-2 Beverley soared in and completed a two-hand follow slam with 18.6 seconds to play. After a timeout, Brown missed a catch-and-shoot 3-pointer, and Beverley pulled down the rebound and was fouled.

But he hit just one of the two free throws.

Al Horford’s 3-pointer from the left corner caromed off the top of the backboard and Brown grabbed the rebound and scored as he was fouled. Then the controversial no-call at the other end sent the Lakers into a frenzy.

In the first 53 seconds of the extra session, Brown made one of two free throws, converted a three-point play, and then drilled a pull-up 3-pointer.

The Celtics were daring Lakers guard Russell Westbrook to shoot throughout the game, and with the Lakers trailing, 117-114, he missed a 3-pointer from the right corner before missing a layup on the next possession.

With the shot-clock running down, Brown hit a tough 18-footer to stretch Boston’s lead to 119-114, and he then added two free throws to essentially finish off the win.

“It was good for us,” Mazzulla said. “It’s always good to snap a losing streak, I think that’s important. You don’t want to take that for granted. I think it was more important to figure out how we needed to handle situations within the game.”