The Bulls used a 19-4 run to take the lead for good and outscored the Celtics 35-22 in the final period. LaVine was the best player on the field with 36 points on 11-for-19 shooting. The Celtics were just 14 for 56 (25 percent) from the 3-point line and lost control of the game with 4 points in the first five minutes of the fourth quarter.

Tatum led the Celtics with 31 points, but by the time he got back into the game with more than six minutes left, Boston had lost the lead. Kristaps Porzingis added 20 points. Dosunmo, who has shut down the Celtics in the past, scored Chicago’s decisive victory with a series of drives against Boston’s sluggish defense.

With the 3-point shot essentially deserting them, the Celtics had to create shots in the paint with dump-ins from Porzingis or attacks on the basket from Tatum. The teams traded balls most of the third period until Porzingis gave the Celtics a 74-68 lead with a corner three-pointer.

Nikola Vucevic countered with a three-pointer and the Bulls then went on a 6-0 run to take a 77-76 lead with 2:31 left.

Porzingis came back with a short jump and Tatum thrilled the Garden with a fast dunk. But here too the Bulls countered with a Dosunmu three. Pritchard and Tatum finished the third period with three-pointers to give Boston an 86-82 lead.

The Celtics were 11 for 39 from the 3-point line after the third period and missed the first four of the fourth period.

Boston had a chance to create distance after taking a 32-24 lead, but wasted a few possessions in a row. Behind two 3-pointers from Patrick Williams, the Bulls went on a 20:9 run and took the lead 44:41. LaVine, who has been the subject of trade rumors for years and is reportedly drawing interest from the Denver Nuggets, kept the Bulls close with 13 points in the final 6:06 of the second period.

After Tatum gave the Celtics a 5-point lead with two free throws, LaVine countered with a 3-pointer and then added another after two free throws from Porzingis. Tatum came back with a contested layup to give the Celtics a 57-54 halftime lead.

Boston missed 18 of its 24 23-point shots, with Jaylen Brown, Porzingis and Jrue Holiday going 0-for-7. The Bulls, who rank second behind the Celtics in 3-point attempts per game, shot 10 for 26, with LaVine and Williams combining for seven.

Tatum led the Celtics with 17 points, while Porzingis added 12 and Derrick White 10. Brown, who had an emotional week after a slump Sunday at his home stadium in Wellesley, went 2 for 7 with 4 points in 19 minutes.

The Celtics were coming off a three-day break and looked strong in the opening period, making just 10 of 29 shots, including 3 of 16 3-point attempts. The ball movement was crisp, but open shots were unsuccessful.

Jayson Tatum was the only Celtics starter to appear in sync, hitting two 3-pointers and scoring 12 points as Boston led 25-21. With Sam Hauser sidelined with back soreness, Celtics coach Joe Mazzulla gave little-used guard Jaden Springer some rare starting minutes, and he responded with strong defense.

Springer played the final three minutes of the first half and six more in the second, grabbing three rebounds. The team’s main concern with Springer is his lack of offense. The Bulls largely played against him, offering open 3-point shots. In one sequence, Chicago’s Lonzo Ball completely ignored Springer to double Jaylen Brown before incurring a foul.

Kristaps Porzingis, who led Sunday’s win over the Washington Wizards with a sore heel, returned to the lineup and scored 12 first-half points as the Celtics gave him numerous chances to exploit the team’s imbalance.