Tyler Burton's career-best 23 points powered Memphis' effort, but a late Boston surge sealed the Grizzlies' defeat.
Jaylen Brown scored 30 points and Boston used a 10-point fourth-quarter run to pull away from the Memphis Grizzlies 117-112 on Friday night.
Luka Garza had a season-high 22 points and Payton Pritchard added 19 for the Celtics, now winners of four straight and 1½ games clear of New York for second in the Eastern Conference.
Tyler Burton led Memphis with a career-high 23 points off the bench. Ty Jerome had 16 points and seven assists. Javon Small and DeJon Jarreau each finished with 13.
Memphis led 103-102 with 5:33 left. Boston outscored the Grizzlies 15-9 the rest of the way. Derrick White hit 11 of his 14 points in the final period.
"There's no other word — amazing," Memphis coach Tuomas Iisalo said. "Guys are competing at a very high level. You see the other teams — Denver in the previous game and Boston in this game — they have to work for everything."
Burton signed a 10-day contract March 12. Friday, he looked like he belonged.
He had 20 points through three quarters, converting open looks even as Boston tried to cross-match onto Memphis's wings. He missed his first two shots. Kept shooting anyway.
"That's what I mean with the trust," Iisalo said. "Everybody was still looking to find him for those open shots."
Iisalo said the continuity between Memphis and its G League affiliate, the Hustle, eased Burton's transition.
"Tyler was already with us during training camp, so some of this is familiar to him," Iisalo said. "He makes up for any nuances with tremendous effort, great attitude, and by seizing the opportunity he's been given."
Jayson Tatum missed his first eight shots. Neither team shot well from deep in the first half. The Grizzlies held Boston to 38.6% shooting in the half, converting 47.8% themselves, and trailed just 55-54 at the break — despite getting outrebounded 29-20 and allowing 12 more Celtics free-throw attempts.
Jerome knocked down back-to-back 3-pointers early in the fourth and Jaylen Wells added a transition dunk off a steal. Memphis led by seven. It didn't hold.
"Unfortunately, we lost the battle on the boards today," Iisalo said. "That has been the decider in many of these games."
Nine Grizzlies were on the injury list Friday. Several have already had season-ending procedures. Boston was without Nikola Vučević, who missed his seventh straight game with a fractured right ring finger.
Small has been one of the steadier pieces through the roster attrition. Iisalo didn't hesitate when asked about his growth.
"He's a very different player than he was at the start of the season," Iisalo said. "He's learned something that was a little foreign to him — combining pushing the pace with having control over the team. He's been one of the best pull-up three-point shooters in the league this season. It's all due to his hard work."
Memphis snapped an eight-game losing streak Wednesday with a 125-118 win over Denver. This one got away late.
The Grizzlies travel to Charlotte on Saturday at 6 p.m. CT on FanDuel Sports Network.