BOSTON — Isaiah Thomas scored 29 of his career-high 52 points in the fourth quarter, setting a club record for points in a period and leading Boston to a 117-114 victory over the Miami Heat on Friday night.
Thomas hit six 3-pointers and converted a three-point play in the fourth quarter and broke the franchise record of 24 points in a quarter set by Larry Bird in 1983 and matched by Todd Day in 1995. Thomas also topped his career high of 44 points he scored on Dec. 20, at Memphis.
He entered the fourth period with 23 points and scored the first 11 of the quarter for Boston, which needed Thomas’ scoring outburst to hold off the Heat.
Al Horford and Jaylen Brown were the only Boston players other than Thomas to score in the final period until Marcus Smart hit two free throws to seal it with 6 seconds left.
Thomas left between the foul shots and received a standing ovation from Boston fans, who chanted “M-V-P!” throughout his run in the fourth quarter. He was 9 for 13 from the field in the fourth period and made all 13 of his free throws in the game.
Horford had 21 points for the Celtics.
James Johnson scored 22 points for Miami, which has lost four straight and seven of eight. Tyler Johnson and Josh Richardson added 19 points each for the Heat.
Both teams were coming off losses the night before, but didn’t show any fatigue in a tight game Friday.
The Heat opened the fourth quarter with five straight points to start an 11-2 run, including a three-point play by James Johnson and a dunk on a putback by Gerald Green. Richardson stole a pass and took it in for another dunk that gave the Heat an 89-84 lead with 9:27 to play.
Thomas erased the deficit with consecutive 3-pointers, then added another from beyond the arc with 7:14 left to put Boston up 93-89. Thomas wasn’t done. He added another 3-pointer to put the Celtics up 101-93 and converted a three-point play with 4:05 left for a 104-98 lead.
The Heat rallied with six straight points to tie it again, but Thomas put Boston right back up with a 1:57 left to make it 106-104 and the Celtics held on.
Heat: Leading scorer Goran Dragic sat out for the second time in three games with back spasms. … The Heat outrebounded the Celtics 27-18 in the first half. … Hassan Whiteside had 17 rebounds in each of the first two meetings against Boston this season. He pulled down eight on Friday and scored 11 points.
Celtics: G Avery Bradley was at home with an illness. “He came down with the latest sickness. He came in and got checked out and we sent him home,” coach Brad Stevens said. … Thomas has scored at least 20 points in 18 straight games, the league’s longest current streak.
Heat: Host Detroit on Sunday night, then head out on a six-game Western Conference trip.
Celtics: Host Utah on Tuesday night. The Celtics have won eight straight against the Jazz in Boston.