BOSTON -- Kevin Garnett's lack of composure didn't lead to a loss. Miami's did.
Boston's emotional leader was slapped with two technicals after he elbowed Quentin Richardson in the jaw with 40 seconds left in the Celtics' 85-76 victory over the Heat in their NBA playoff opener Saturday night.
Garnett faces a possible suspension and could miss the second game Tuesday night in Boston.
He said he was concerned that Paul Pierce, who had fallen in front of the Miami bench, had hurt his shoulder and wanted to clear space around him. Richardson came by and said something and Garnett struck him on the left side of the face with his left elbow.
"I was just concerned about Paul. You make your bed, you have to lay in it," Garnett said about a possible suspension. "I am smarter than that. I have to keep my composure in a situation like that."
The Heat's loss of composure lasted much longer.
Leading 61-47 with 7:02 left in the third quarter, they fell behind 71-68 with 3 minutes gone in the third. They finished with 22 turnovers that resulted in 38 Boston points.
"The damage for us was done long before [the skirmish]," Miami coach Erik Spoelstra said. "We just did not show a lot of composure. ... To play to that kind of pressure, a little bit of duress, a little bit of adversity, we did not respond well to it."
Before his ejection, Garnett had played well with 15 points and nine rebounds. One of the NBA's noted trash talkers, he found himself in the middle of a swarm of Heat players when Pierce fell down. There was shoving and technicals were called at first against Miami's Udonis Haslim and Boston's Glen Davis.
Then Garnett and Richardson got into it with Jermaine O'Neal nearby.
"I was trying to get over there to take the ball out of bounds," Richardson said. "I said to Jermaine, 'He [Pierce] is OK,' because I knew nobody touched him. Is he taking a break like he does so many times?"
Dwyane Wade had a simple explanation: "We're in the playoffs, that's all. Just a couple of basketball players acting tough."
Trailing 44-41 at halftime, the Celtics held the Heat to 32 points in the second half. And with substitute guard Tony Allen shadowing Wade, the Heat star scored 26 points after averaging 33.7 in three regular-season games against Boston.
"Tony and Baby [Davis] I thought, defensively, changed the game for us," Celtics coach Doc Rivers said.
Allen also scored a playoff career-high 14 points, and Pierce led Boston with 16. Richardson added 15 for Miami.
Miami allowed the second fewest points in the regular season, an average of 94.2, but was outscored 21-10 in the fourth quarter.
And Garnett had a big game after missing last year's playoffs because of a knee injury that required offseason surgery. Saturday's playoff game was his first since Game 6 of the 2008 NBA finals, a 131-92 win over the Los Angeles Lakers for Boston's 17th NBA championship. In that finale, he had 26 points, 14 rebounds, four assists, three steals, a block and no turnovers.
This year, both teams stressed that the playoffs were a new season and what happened before didn't matter.
They were right.
Boston won after going 3-7 in its last 10 games. Miami lost after going 12-1 in its final 13 games and 8-0 in its last eight games on the road.
"When you get Game 1 at home, you don't find yourself back pedaling and pressuring yourself to go out on the road and win," Pierce said.
Trailing by two starting the final quarter, the Celtics tied the game at 68 on two free throws by Rajon Rondo, who had 10 points and 10 assists.
Then the 289-pound Davis gave Boston the lead for good with an acrobatic layup followed by a backward somersault after he hit the floor when fouled by O'Neal. Davis hit one of two shots.
Miami followed with a 24-second violation before a tip-in by Davis gave Boston a 73-68 lead. The Heat then missed their next two shots and Rasheed Wallace stretched the lead to six with one free throw.
Wade followed with a free throw, but Allen increased the lead to 76-69 with a layup. Michael Beasley hit a shot for the Heat but any chance they had faded as the Celtics scored the next five points on a dunk by Garnett, a free throw by Davis and a layup by Rondo.
In the first half, the Heat dominated the boards 23-15 and stifled the Celtics on defense to take a 44-41 lead at intermission. Miami ended the first quarter with a 29-28 edge, then Boston missed 10 of its first 12 shots in the second. But the Celtics rallied at the end, scoring the last five points of the period, the final two on a 13-foot jumper by Rondo at the buzzer.
Boston also used a late surge to cut Miami's biggest margin of the game, 14 points, in the third quarter. After Wade's layup made it 61-47 with 7:02 left in the period, the Celtics outscored the Heat 17-5 the rest of the way and trailed by just 66-64 going into the fourth. Pierce had the last seven points in the comeback and missed a 3-pointer as the buzzer sounded.
"I think it's going to be an emotional series," O'Neal said.
It already is.
Rondo played despite flulike symptoms that kept him out of practice Friday. ... Allen's previous playoff high was nine points against Indiana on April 30, 2005. He started the day with 48 points in 32 playoff games. ... The Celtics, last in offensive rebounds in the NBA, had just two in the first half. ... Richardson hit the only 3-pointer in the first half. Boston's Ray Allen missed all four he tried in the first two quarters. ... Aerosmith lead singer Steven Tyler, a Boston-area resident, attended the game.