The short-handed Celtics fell to the Indiana Pacers 133-131 Monday night at Gainbridge Fieldhouse.
Jaylen Brown finished with a season-high 40 points on 17-of-26 from the field (3-of-4 from deep) to lead Boston, who were without Jayson Tatum (ankle) and Sam Hauser (shoulder).
"He stepped up and didn't force anything," C's coach Joe Mazzulla said of Brown. "He let the game come to him. He scored in many different ways."
Kristaps Porzingis returned to the lineup following being poked in the eye during the team's 118-101 win over Indiana Saturday, to record 19 points (6-of-13), five rebounds and seven assists.
Jrue Holiday had 21 points on 9-of-16 shooting to go along with six assists, while Payton Pritchard chipped in 14 points, seven rebounds off the bench for the Celtics -- who fell to 28-8 on the season.
For the Pacers, they played much of the contest without their All-Star Tyrese Haliburton after he sustained a left hamstring strain when driving to the hoop and slipped into a split with 3:10 left in the second quarter. He was then carried into the locker room by two teammates and did not return.
"That was a very deflating moment," Pacers coach Rick Carlisle said in his postgame comments. "[But] this was an important game. Every game that we play has the ability to be a season-defining game."
Bennedict Mathurin led Indiana with 26 points (5-of-9 from 3), including the game-winning free throws. Former Celtic Aaron Nesmith netted 17 points, Myles Turner registered 16 points, eight rebounds and Buddy Hield scored 15 points for the Pacers -- as they improve to 21-15 and split a two-game home series in the process.
It was a close battle from the opening tip, before Boston grabbed it's largest lead of the night following an 18-7 run capped off by a Brown 3-pointer to end the first half and take a 68-58 advantage into the break.
The Pacers went ahead at the 7:17 mark on a 26-15 spurt to start the third and stayed in front the rest of the period.
The Celtics trailed 110-103 on a 7-2 burst by Indiana -- their largest margin -- to begin the final frame, but the visiting team responded with a 11-5 run to get within one. Porzingis hit a go-ahead 3-pointer to put Boston up 131-129 (their only lead of the quarter), before T.J. McConnell tied up again on the next play.
Brown missed a 14-foot pullup but not before Hield was whistled for a foul on the C's star wing with 3.2 seconds left to play after neither team converted a field goal on back-to-back possessions.
Indiana challenged the foul on Hield and was awarded the ball after a review overturned the call with the game still knotted at 131.
Mathurian was fouled by Porzingis attempting a 3 before the final buzzer and hit the first two free throws but missed the third on purpose leaving 0.3 ticks on the game clock.
Derrick White (13 points, six assists) got a good look at an alley-oop inbound lob to Luke Kornet, who missed the tip as time expired -- giving Boston their second loss to the Pacers in four meetings so far.
"We all played a relatively decent offensive game," Mazzulla said, "but we all have to be better on defense."
The Celtics head back home were they are undefeated (17-0) to host the Minnesota Timberwolves (25-10) at TD Garden Wednesday night in a 7:00 pm ET tip-off.
Boston hit 52.2% from the field, including 17-of-35 (48.6%) from long distance, while the Pacers were 52.7% from the floor and 19-of-40 (47.5%) from 3. The Celtics won the rebound battle 42-39 and outscored the home team in the paint 52-44. Indiana had 29 assists (13 turnovers) on 48 baskets to the C's 26 dimes (15 turnovers) on 47 made shots.