BOSTON _ The Miami Heat went big in free agency. And Hassan Whiteside could yet pay proper dividends when Pat Riley surrounds him with a representative roster. But the long and short of it on Friday night at TD Garden was that short prevailed.
In a big, big, big way.
With 5-foot-9 Isaiah Thomas raining rallying 3-pointers on the way to a remarkable 52-point night, the Boston Celtics pushed their way to a 117-114 victory, the Heat's seventh consecutive road loss.
Eclipsing Carmelo Anthony's 35 points as the most by a Heat opponent this season, Thomas shot 9 of 13 on 3-pointers and 13 of 13 from the foul line, taking advantage of a Heat backcourt depleted by the back spasms that sidelined Goran Dragic for the second time this week.
He became the eighth player to record a 50-point game against the Heat in the franchise's 29 seasons, counting regular season and playoffs, and the fifth Celtics player to do it, joining Larry Bird, Kevin McHale, Sam Jones and Paul Pierce.
The Heat power game, by contrast, was limited, with Whiteside closing with 11 points and eight rebounds, not even on the court in a small-ball finish.
Even with James Johnson scoring 22 points and Tyler Johnson and Josh Richardson 19 points apiece, the Heat had no answer for the most dynamic inch-for-inch presence in the NBA, Thomas' effort making the 19 points from Celtics center Al Horford less than even secondary.
The Heat opened the fourth quarter with an 11-2 run to take an 89-84 lead with 9:27 to play. But the Celtics, sparked by a pair of Thomas 3-pointers, responded with an 11-0 run of their own for a 94-89 lead with 6:43 to play.
The Heat later moved within 101-98 on a Tyler Johnson 3-pointer, with a Josh Richardson 15-foot pull-up with 2:36 to play and a Wayne Ellington transition layup with 2:12 to play tying it 104-104.
Thomas responded with a driving finger roll with 1:57 to play to give the Celtics a 106-104 and push Thomas past his previous scoring high of 44 points. Thomas then came up with a steal and was fouled, going to the line with 1:23 left, where he converted both free throws for a 108-104 Celtics lead.
But back came Tyler Johnson with a jumper that pulled the Heat within 108-106 with 1:17 left. That, however, is where the rally ended.
With Dragic unable to push through back spasms for a second consecutive night, the Heat moved to their 13th starting lineup of the season, with Josh Richardson shifting from Thursday's start at shooting guard to a Friday start at point guard.
That had Rodney McGruder back in the starting lineup, alongside Richardson, Whiteside, Winslow and Luke Babbitt.
The Celtics also were shorthanded, with Avery Bradley sent home due to an illness, with Marcus Smart starting in his place.
Both teams were playing on the second night of a back-to-back set with the Heat losing Thursday in Charlotte and the Celtics losing Thursday in Cleveland.
The Heat return home for a Sunday game against the Detroit Pistons at AmericanAirlines Arena, before heading out for a six-game trip that opens Tuesday against the Phoenix Suns.
In addition to being without Dragic, who remained on the trip, the Heat remained without guard Dion Waiters and forward Josh McRoberts, with Chris Bosh away from the team since failing his preseason physical.
The Celtics, behind invigorated play from Horford, went into the fourth quarter up 82-78, a stage when the Celtics had attempted 20 free throws to the Heat's five.
Thomas had 19 points at the intermission, with the Celtics overcoming a seven-point halftime deficit to take a 52-48 halftime lead. Thomas was 3 of 3 on 3-pointers and 8 of 8 from the line over the first two periods.
The Heat were able to hang close with a 27-16 first-half rebounding advantage, with Winslow with eight to that stage and Whiteside with seven.
The teams stood tied 25-25 at the end of the opening period, with Winslow scoring seven in the quarter after shooting 0-for-9 in Thursday's loss to the Hornets, this time taking his game closer to the rim. Tyler Johnson helped compensate for the absence of Dragic with four first-quarter assists.
The Celtics entered with a 2-0 lead in the four-game season series, with both victories at AmericanAirlines Arena.
The Celtics entered having won five in a row from the Heat, including the previous two meetings at TD Garden.
The game concluded the Heat's seventh back-to-back set of the season, with a 1-5 record on the second nights of such pairings entering the night.
