MIAMI (AP) — Paul Pierce demanded the ball for the last shot. The Boston Celtics were rewarded.

And the much-anticipated offseason of 2010 is closer than the Miami Heat ever wanted.

Pierce's 21-foot jumper at the buzzer — with injured Heat star Dwyane Wade watching helplessly from the bench, suffering from his second bad cramp in the final minutes — gave the Celtics a 100-98 win over Miami in Game 3 of the teams' Eastern Conference first-round playoff series Friday night.

Boston leads the best-of-seven 3-0, and will go for the sweep Sunday afternoon in Miami.

"That's a shot I hit a number of times in playoffs and regular season," Pierce said after getting mobbed by teammates in an on-court melee. "I told the coaches, 'Give me the ball on the right side.' I got to my sweet spot, made sure there wasn't any time left and drained it."

Easy as that. The Celtics loaded the court with shooters and ran a bunch of cuts, all of which were merely theater.

The moment would belong to Pierce.

"It was just Paul," Celtics coach Doc Rivers said. "He wanted it. All the movement that you saw, it was just false movement."

No team has ever rallied from an 0-3 deficit in a series, and Miami might have even bigger problems than that. Wade hurt his left calf after missing a 3-pointer with 14 seconds left, with replays showing he landed on Celtics guard Ray Allen's foot. Wade — who changed jerseys during the game because he was sweating so much — crumpled to the court and was carried off by reserve center Jamaal Magloire and trainer Jay Sabol, then chugged a cup of Gatorade in case the game went to overtime.

It didn't.

Pierce saw to that.

"Everything moves fast when the clock is winding down," Pierce said.

For the Heat, so is the season.

Pierce finished with 32 points, while Allen added 25 for the Celtics, who got 17 from Rajon Rondo and 16 from Kevin Garnett. Boston has won 14 of the last 15 games against Miami, including all six this season.

Wade finished with 34 points, eight assists and five rebounds for the Heat, who rallied from a nine-point deficit in the fourth quarter to take the lead, then fell victim to Pierce at the end.

"We certainly fought the fight in terms of bringing the appropriate level of intensity to the game," Heat coach Erik Spoelstra said. "That was there. Couldn't ask for much more in terms of effort plays and just bringing the fight."

Boston led 85-76 early in the fourth, seeming to be in full control of the game, and with it the series.

On the ropes, the Celtics poised to land the knockout blow, the Heat found a way to counter.

Beasley scored six of the next eight Miami points to spark the rally, and when Wright hit two foul shots with 3:46 left after Pierce shoved him in the back jostling for a rebound, the Heat were up 92-91.

Then the fight really began.

After two ties, Allen swished a 3-pointer off a quick catch-and-shoot with 2:31 left, putting Boston back up 95-94. Pierce made a 3-pointer — he missed a jumper, but Rondo swooped in, got the rebound and kicked the ball back out — to give Boston a three-point lead, only to have Wright answer 13 seconds later with a 3 from near the Celtics' bench.

With that, Wade clenched both fists.

He just couldn't land the big shot when he needed it most.

"It is, obviously, a very tough loss," Spoelstra said.

Just like in Games 1 and 2, when the Celtics used two colossal runs — 34-10 last Saturday, 44-8 on Tuesday — to put the Heat away, this one had some signs early that Boston was going to pull away from Miami quickly.

And there were some residual effects of those games, too, much of which stemmed from the Garnett-Pierce-Quentin Richardson dustup with 40 seconds left in Game 1.

Garnett, who returned from a one-game suspension for elbowing Richardson in that scrum, and Pierce both got booed lustily for much of the game. Plus, when Richardson got his second foul midway through the opening quarter, Pierce walked downcourt with him, about 20 feet to his right, the two longtime adversaries exchanging words the whole way.

Emotions ran high, for certain.

The Heat led 29-24 late in the opening quarter when Wade found Wright for a spectacular, reverse, alley-oop slam that sent the crowd and most of the Miami bench to their feet in simultaneous celebration.

And somehow, it seemed like Boston was the team inspired by the scene.

The Celtics immediately went on a 15-2 run over the next 5 minutes, as the Heat managed to go 1 of 6 from the field in that stretch with five turnovers — which Boston turned into eight points. It all meant the Celtics led 39-31 midway through the second quarter, surely prompting a sense of "Here we go again" from the Heat faithful.

Not quite.

Even without Wade scoring in the second quarter — he was 0 for 3 — the Heat had enough to close the half on a 18-9 spurt, taking a 49-48 lead, thanks in part to silly play by Rondo. He cost Boston a basket late in the half when, after flipping the ball to Allen on what was a 2-on-0 break, stopped to hipcheck Wade and send the Heat guard flying. It was Rondo's third foul, and Allen's dunk came off the board.

The third quarter was mostly back and forth, until the final moments.

That's when Boston took control with an 11-2 spurt. Pierce hit a 25-footer with 1.7 seconds left in the period and the Celtics matched their largest lead, 80-72 entering the fourth.

"We've just got to go out there Sunday and give them another fight," Wright said. "That was definitely a backbreaker, right there."

NOTES: Jermaine O'Neal was 1 of 7, making him 5 of 31 in the series. ... NBA commissioner David Stern was in attendance, part of his postseason tour around the league. ... Celebrities at the game included tennis star Serena Williams, Louisville coach Rick Pitino and NBA veteran James Posey — who won championships with the Heat in 2006 and Celtics in 2008. NFL rushing champion Chris Johnson of the Tennessee Titans said on Twitter he had tickets so close to the court the "ball rolling by my feet."