Lauri Markkanen scored 28 points with 10 rebounds and the Utah Jazz rallied late to take a 118-117 victory over the Boston Celtics on Saturday night in Salt Lake City.
Jaylen Brown topped Boston with 25 points and Grant Williams scored 23, but his last-second game-winning attempt near the rim was blocked by rookie Walker Kessler.
Despite the loss, Boston (49-23) clinched a playoff spot, while Utah (34-36) remained in postseason contention in the crowded Western Conference field.
Kessler finished with 12 points, 14 rebounds and three blocks, Kelly Olynyk had 13 points, 13 rebounds and six assists, and Talen Horton-Tucker contributed 19 points, seven rebounds and five assists.
Boston led by as many as 19 points and was up by six with 2:31 after a 3-pointer by Williams, who hit 7 of 12 shots from deep.
But the Jazz, playing their first game since Monday, returned after a six-game road trip and rallied past the road-weary Celtics. It was Boston's third game in four nights.
Utah, which converted 17 offensive rebounds into 20 points, used a late 6-3 push to pull within four, 114-110, with under two minutes remaining.
Brown was then called for a flagrant foul, but Kessler missed both free throws. The Jazz salvaged the possession, however, thanks to the fourth 3-pointer of the night by Ochai Agbaji to cut the lead to one with 1:33 left.
Brown and Markkanen then exchanged treys, before Horton-Tucker put Utah ahead by one with a layup with 35.3 seconds remaining.
Tatum missed a 3-point attempt on the ensuing Boston possession, but the Celtics got the ball back with five seconds remaining after Horton-Tucker lost the ball out of bounds.
Kessler then atoned for his missed late free throws by blocking Williams' short last-second jumper to preserve the win.
Boston, which won in Portland on Friday night, jumped out to a commanding 53-34 lead.
That deficit quickly evaporated as Utah went on a 23-5 run to pull within one. Tatum, who had 15 points, put the Celtics up 64-57 heading into halftime with six straight points.
Blake Griffin gave the Celtics a 67-61 lead with a 3-pointer early in the third. The Jazz answered with a 10-2 run, highlighted by back-to-back treys from Agbaji, to snatch the 71-69 lead, setting up a back-and-forth finish.
Tatum became the first player in the NBA to reach the 2,000-point mark this season.
--Field Level Media