But the tension and drama had just begun. Two missed free throws and a rare 5-second violation gave the Pelicans a chance to win in the final seconds. Luckily for the Celtics, CJ McCollum’s floater made it through and the Celtics secured a 120-119 win.

Jayson Tatum led the Celtics with 38 points on a season-high 30 shot attempts, but also missed two free throws that would have given Boston a 5-point lead with 13.4 seconds left. White fouled McCollum before he could fire a potential 3-pointer to tie the game, and he sank both free throws.

After a timeout, all the Celtics had to do was inbound the ball and then commit a foul, and the game was probably sealed. But White was called for a 5-second violation before he could call a timeout. He thought he had called it in time, but the officials didn’t budge and gave the Pelicans the ball with a chance to win.

The Celtics came off the floor in relief. It was a difficult phase, especially at home. They had suffered a significant defeat against the Sacramento Kings on Friday and had problems again on Sunday as clear favorites.

“Every season is different, and so is our journey,” Celtics coach Joe Mazzulla said. “If you look at it in perspective, there are things we do well. The most important thing is to win the game and make the necessary plays even when things aren’t going well. Each season brings different challenges. Every season brings different opportunities and the situation we’re in right now, we just have to fight through it.”

Boston never led by more than 5 points and the Pelicans used a 3-pointer from Jose Alvarado to take a 100-98 lead with 8:35 left. The Celtics countered with a 16-10 run to take a four-point lead with 3:55 left before forcing a shot clock violation.

They now had a chance to take control, but White picked up a backcourt inbounds pass from Jrue Holiday and turned quickly as his leg hit the ball, sending it out of bounds. The Pelicans then responded with a three-pointer from Zion Williamson and another three-pointer from Alvarado to take the lead.

White sat distraught on the bench before being comforted by teammate Al Horford. White grabbed a crucial defensive rebound and then sank those two free throws before the 5-second mark in what was an emotionally draining stretch.

“It’s frustrating, especially the unforced (errors),” he said. “Catch the ball, easy thing. It was nice to see the guys making plays down the stretch. We were able to do whatever it took to achieve victory, even if it wasn’t quite as we planned. It’s good to get this win.”

On the 5-second violation, White contradicted official Brian Forte, who said he waited too long to call a timeout.

“I took the ball out a lot and thought I had a pretty good internal clock,” White said. “He said he got to five and I don’t know how. But luckily it didn’t cost us anything.”

The Pelicans didn’t play like a team headed for the draft lottery. For the first time in 41 games, Dejounte Murray, Trey Murphy and Williamson, three projected starters, played together. And the first two gave the Celtics fits.

Murray, who entered Sunday with 30 3-pointers for the season, scored five times in the first quarter and added another in the fourth. Murphy tied his season high with five 3-pointers and carried the Pelicans for most of the second half. New Orleans made 46.5 percent of its shots and 45.9 percent on 3-pointers against a shaky Celtics defense.

But for the first time since November 29, the Celtics won a complete game against the top-seeded Cleveland Cavaliers, who lost at home to the Indiana Pacers. Despite a 12-8 record in their last 20 games, the Celtics still have the third-best record in the NBA and were thankful they were able to make enough plays to avoid another upset.

“Maybe you don’t want to play your best basketball in early January,” Tatum said. “We’ve seen this before. We still have a lot of time to return to our identity. It shouldn’t be easy and we give everyone the best. New Orleans played really well. I don’t think they played like that the whole time. But it was a good test for us. That’s exactly how it will be.”

Gary Washburn is a Globe columnist. He can be reached at [email protected]. Follow him @GwashburnGlobe.