With the win, the Heat extended their win streak to 23 games, passing the 2007-08 Houston Rockets to lay claim to the second-longest winning streak in NBA history. They now need 10 consecutive wins to tie the 1971-1972 Los Angeles Lakers' record of 33 straight victories in a season.
James finished with 37 points, 12 assists, seven rebounds, two steals and two blocks, spoiling an inspired effort by Celtics forward Jeff Green.
Making his fourth start of the season in place of an injured Kevin Garnett, Green finished with 43 points, seven rebounds, two assists, two steals and four blocks. Paul Pierce added 17 points, eight rebounds, eight assists, one steal and one block in the losing effort.
The Celtics led by double digits early, but the Heat went on a 12-4 run to trim the deficit to six points at halftime. Two quarters in, Boston was out-shooting Miami (62 percent to 49 percent) and winning the battle of the boards (21 to 16). The Heat managed to stay within striking distance by scoring 14 points on 11 Celtics turnovers.
Miami came out on fire in the second half, scoring six unanswered points within two minutes, ultimately taking the lead, 61-59, after a Celtics timeout. Boston reclaimed its advantage before the end of the quarter, going on a 23-17 run to close the period up 82-78.
Down four heading into the fourth, the Heat were in familiar territory. Miami had trailed or been tied in the fourth quarter in 11 of its last 22 games, yet still outscored opponents by an average of 11.7 points, as noted by Eric Reid of Fox Sports Florida.
Boston jumped out to a 93-86 lead in the final period, but the Heat came right back, going on a 15-7 run in less than six minutes to take a 101-100 lead with less than three minutes remaining left to play in regulation.
Though the Celtics re-took the lead on a three from guard Avery Bradley, James responded with consecutive baskets, including the game-clincher.
Coming into the contest, the Heat were 1-1 against the Celtics this season. They beat Boston in their first regular-season matchup, 120-107, but lost a 100-98 overtime thriller at TD Garden on Jan. 27.
Miami's next 10 games are against, in order, Cleveland, Detroit, Charlotte, Orlando, Chicago, New Orleans, San Antonio, New York, Charlotte (again) and Philadelphia. If they manage to win all of these contests, they will have to defeat Milwaukee on April 9 to set a new NBA record.
The streak lives on.