MIAMI - Dwyane Wade knew his regular-season numbers against Boston were lacking.

He also knew that wouldn't matter in the playoffs.

And Game 1 — which seemed more like Round 1 — of what's already an emotionally charged series went to Wade and the Miami Heat.

Wade scored 38 points on 14 of 21 shooting, James Jones set a Miami postseason record with 25 points off the bench, and the Heat beat the Celtics 99-90 on Sunday to open their Eastern Conference semifinal series.

"It's a big game. It's Game 1, at home," Wade said. "You've got to take care of home court. These guys expect this from me. I wasn't giving it to them in the regular season versus them and I wanted to come out today and be a leader."

LeBron James finished with 22 points, six rebounds and five assists for Miami, which led by as many as 19 before a fiery finish that saw plenty of players jawing at each other — more than that in some cases. Paul Pierce was ejected with 7 minutes left, after picking up two technicals in skirmishes with Wade and Jones within a span of 59 seconds.

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Ray Allen scored 25 points for Boston, which lost for the first time in five games this postseason. Pierce scored 19 and Delonte West finished with 10 for the Celtics, while Rajon Rondo and Kevin Garnett were held to a combined 14 points on 6-for-19 shooting.

Game 2 is Tuesday in Miami.

It was physical throughout, with West earning a technical and Jermaine O'Neal picking up a flagrant foul along the way, before things really got hot in the fourth. Pierce took offense with a hard foul by Jones, each getting double-technicals there, and Pierce and Wade — who have a bit of history — renewed acquaintances not long after that.

Referee Ed Malloy called both for double-technicals, and Pierce was screaming as he departed. Boston coach Doc Rivers said he thought Jones and Wade went at Pierce too aggressively on the two plays that ended his forward's night.

"I thought both were flagrant fouls, personally, and I don't think we should react to either one," Rivers said.

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The Celtics tried to rally. Allen made a 3-pointer to get within 90-82, but Chris Bosh and Wade had Miami's next two baskets, restoring a double-digit lead that wasn't again threatened.

"Every game is going to go like this," Wade said. "We look forward to the challenge."

Wade averaged 12.8 points on 28 percent shooting against the Celtics in four regular-season matchups, his worst numbers in both categories against any opponent this season.

Whatever wasn't working then, well, it was fixed for Game 1.

He had nine field goals and 23 points by halftime — while the entire Boston starting five combined for eight field goals and 21 points in the first 24 minutes. He had a steal to set up Mario Chalmers' layup with 0.1 seconds left in the first quarter that put Miami up 20-14, and added a more spectacular buzzer-beater near halftime.

Heat coach Erik Spoelstra wanted a 20-second timeout to set up the final possession of the half, only to get overruled — surely without complaint, either. Wade waved it off, then kept waving his arm to clear his teammates away, setting up a drive past West for a bank shot with 0.8 ticks remaining that put Miami ahead 51-36 at the break.

Boston was completely out of sorts, perhaps rusty from sitting around for a week after sweeping the New York Knicks, and partly because Miami's defense bottled up everything the Celtics tried. Rondo was on the bench with three fouls for the final 11 minutes of the half, and the Celtics missed 20 of their first 26 shots from the field.

And then there was the James factor — Jones, that is.

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He drew Rondo's third foul on a play where he ended up sprawled out under the Boston basket, grabbing his lower back and writhing in pain. Jones inflicted hurt the rest of the quarter, shooting 4 for 5 from 3-point range in the second period alone.

Miami extended the lead to 19 early in the third, before Boston put together its best stretch of the day, peeling off 12 straight points and getting within 55-48 on a layup by Pierce with 7:20 left in the quarter.

The Heat outscored Boston 21-14 throughout the remainder of the third, going up by as many as 18 on a pair of free throws by James with 40 seconds left before taking a 76-62 lead into the final 12 minutes.

NOTES: Including the April 10 victory, Miami has now won consecutive meetings with Boston for the first time since early 2007. ... Boston was without Shaquille O'Neal (calf) and Miami remained without Udonis Haslem (foot), both still out with injuries, though it seems both could be returning at some point in this series — maybe even Tuesday. ... Plenty of celebrities showed up, including Diddy, Gloria Estefan and rappers Drake and Rick Ross. ... Rivers, on former Boston assistant Tom Thibodeau winning the NBA's coach of the year award: "He came in and did his job."