MIAMI -- Isaiah Thomas was in a considerable amount of postgame pain.
He made the Miami Heat do some hurting as well.
Thomas scored 25 points off the bench -- one more than all of Miami's reserves combined -- and the Boston Celtics dealt the Heat's playoff chances a blow with a 100-90 victory on Monday night.
"I was just telling myself that pain is only temporary," said Thomas, who bruised his right elbow and lower back on a nasty fall in the final minutes. "If you don't think about it you can kind of get through some things."
Brandon Bass added 14, Luigi Datome scored 13 and Kelly Olynyk finished with 10 for Boston. Olynyk also was the recipient of a two-handed shove from Miami center Hassan Whiteside, who lost his composure midway through the third quarter and got ejected for the second time in his last four outings.
"He's going to have to learn," said Heat guard Dwyane Wade, who led all scorers with 34 points and didn't hide the team's disappointment with Whiteside afterward. "He's going to learn the hard way. Hopefully he changes his mentality quick."
Michael Beasley scored 14 and Mario Chalmers added 12 for the Heat, who stayed in ninth in the Eastern Conference and missed a chance to climb to the No. 7 spot in the muddled race at the bottom of that bracket. The Heat got a pregame lift from the return of Chris Bosh to the team's bench for the first time since he was ruled out for the season last month because of blood clots on a lung.
Thomas has appeared in 10 games, all off the bench, since the Celtics acquired him in a trade last month. He has averaged 21.4 points and Boston is 6-4.
Thomas hit maybe the biggest shot of the night -- a 3-pointer with 2:36 left that gave the Celtics a 96-87 lead.
"Thomas had a great impact on that second half," Heat coach Erik Spoelstra said. "We had trouble corralling him on whatever the pick-and-roll coverage was ... and if he did miss or somebody else missed, they definitely won the 50-50 battle."
Upset over a non-call on one of his drives, Whiteside didn't get back on defense midway through the third and Bass was able to get a dunk because the lane was open. And then Whiteside made it worse, coming back the other way and shoving Olynyk.
Whiteside was assessed a flagrant-2, an automatic ejection, and the injury-ravaged Heat got even more short-handed.
"We all go through ups and downs. We all get mad," Beasley said. "You have to learn how to control it."
With the Heat forced to go small, Boston happily took advantage. The Celtics got 14 points in the paint in the final quarter.
"We are not playing with any cushion, we are playing to just try and get back in it," said Celtics coach Brad Stevens, whose team is now just two games out of a playoff spot. "We have to play really well over the last 20 games to have a chance."
Celtics: Boston improved to 8-5 in the second night of back-to-backs. The Celtics still have five of those grueling sets left this season, all of them being the home-road variety. ... No Boston player got into double figures until 5:23 remained in the third quarter, when Thomas made a pair of free throws to reach 10 points.
Heat: Udonis Haslem departed the morning shootaround with icepacks strapped to his left wrist, knee and ankle. Not surprisingly, he didn't play, and neither did Goran Dragic -- still day-to-day with a lower back contusion. Dragic has missed two straight games. ... Whiteside has gotten a technical or flagrant in each of his last four outings.
INSIDE THE BOX
Boston outrebounded Miami 43-32, outscored the Heat 42-24 in the paint and had a 14-6 edge in fast-break points.
Celtics: Host Memphis on Wednesday.
Heat: Host Brooklyn on Wednesday.
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