Anfernee Simons' 39-point performance off the bench, including 18 in the fourth quarter, led the Boston Celtics to a thrilling 119-114 comeback victory over the Miami Heat on Thursday night. Jaylen Brown contributed 27 points, and Sam Hauser added 17, outscoring Miami 36-21 in the final quarter. This was the Celtics' second-largest comeback of the season, mirroring their 20-point comeback against Indiana on December 22. Simons' 39 points marked the second-highest scoring game for a reserve this season, with Utah's Brice Sensabaugh scoring 43 points in a loss to Chicago. He also became the fourth Celtics player in the last 50 years to score at least 39 points off the bench, joining legends like Larry Bird, Todd Day, and Payton Pritchard. Norman Powell led the Heat with 26 points, while Bam Adebayo and Tyler Herro each scored 22. Andrew Wiggins added 16. Simons' 11 consecutive points in the fourth quarter narrowed the gap, and Hauser's crucial 3-pointer with 5:21 left gave the Celtics their first lead since the game's opening minute. The game's momentum shifted multiple times, but Brown's 3-pointer with 4:05 remaining secured the Celtics' victory. Miami's strong start, a 28-9 run, put the Celtics in an unusual early position, facing a 19-point deficit within seven minutes. This deficit matched the Celtics' largest first-quarter deficit in 304 games, last seen on December 21, 2022, when they trailed Indiana by 20. The Heat played without starting point guard Davion Mitchell (left shoulder contusion) and key player Jaime Jaquez Jr. (left knee soreness).