Tatum scored 21 in the second half to help Boston rally for its fifth win in six games.
The Pelicans fell to 6-17 on the road.
Tatum slowly walked down the hallway from the locker room with the rest of his teammates for the start of the second half, then spurred a 22-7 run.
“The ball got really stagnant in the second half,” Ingram said.
The Pelicans had opened a 42-24 lead with just over four minutes left in the second quarter and led 46-39 at halftime.