BOSTON – Miami Heat guard Dwyane Wade's final shot of the game, a three-point attempt, hit the front of the rim, hit the backboard and did not fall in.

The Boston Celtics won Game 4 of the Eastern Conference finals 93-91 in overtime.

"Red wasn't going to let that go in, you know," Rivers said of late Celtics icon Red Auerbach. "Not in the Boston Garden."

You can believe that, or you can just believe the shot didn't fall. But know this: This incarnation of the Celtics refuses to fade gently into the twilight. Where ever they are going — perhaps to the NBA Finals, perhaps not — it will be with a fight.

So it was that Game 4 devolved from an offensive exhibition to a physical struggle. Star forwards LeBron James of the Heat and Paul Pierce of the Celtics fouled out in overtime, and six others finished the game with four or five fouls.

The best-of-seven series is tied at 2-2, with the home team winning each game, as it has been in the Western Conference finals between the Oklahoma City Thunder and San Antonio Spurs.

The Celtics-Heat series has been reduced to a three-game series. Game 5 is Tuesday in Miami (8:30 p.m. ET, ESPN). Boston still faces an arduous task. It must win at least one on the road. Only 14 teams in NBA history have come back from a 2-1 deficit.

"We haven't put together a 48-minute game yet," Boston forward Paul Pierce said. "We're hoping we can put together a full game in when we get down to Miami."

Facing pressure, Miami may be close to bringing back All-Star forward Chris Bosh. Bosh hasn't played since straining his a muscle in his lower abdomen against the Indiana Pacers in Game 1 of the Eastern Conference semifinals May 13, three weeks ago. ESPN reported Monday morning that Bosh will be activated for Game 5 and would play barring a setback.

Before Game 4, Heat coach Erik Spoelstra said there was no update on Bosh, who has been listed as out indefinitely.

Sunday's game will be known for wild swings: Boston had an 18-point lead that evaporated in the fourth quarter. It will be known for Rajon Rondo's 10 first-half assists, and James' three-pointer with 37.5 seconds that sent the game into overtime.

It will be known for great offense and great defense, for bad offense and bad defense and for two important offensive rebounds by Boston's Mickael Pietrus on the same possession, a scoreless Boston possession that took more than 60 seconds off the clock in overtime.

"An instant-classic type of game," Pierce said. "A good old class bar fight."

It will also be known for the two leading scorers fouling out. Pierce, who had 23 points, picked up his sixth foul 38 seconds into overtime. James, who had 29 points, fouled out with 1:51 left.

James sat at his locker postgame flabbergasted. In 794 regular-season and playoff games, James has fouled just four times - three times with the Cleveland Cavaliers. His last before Sunday was April 2, 2008.

"I don't foul out," James said. "If I'm going to foul out, that sixth foul, I wish I would have earned it, and it had actually been a foul on me. Whatever."

On the play that sent James to bench, he tried to post up Pietrus near the basket. Pietrus fell to the ground and James fell on top of him. Referee Joey Crawford immediately called the foul on James.

"It's very difficult because I know how to play the game of basketball, and I don't need an advantage of holding somebody or pushing somebody down," James said in the locker room. "But whatever, we lost."

Fifty-eight fouls were called, 12 of them on the offenses. It was not a pretty game. Boston dropped 61 points in the first half but 32 total in the second half and overtime. Miami shot 42.5%, Boston 41.2%.

"The play-calling was all over the place, as far as the refs," Celtics forward Kevin Garnett said.

Rondo gave another advanced-level seminar in point guard play. He carved up the Miami Heat's defense with another brilliant performance, dominating the game by directing an impressive offensive game plan in the first half. He finished with 15 points and 15 assists.

Spoelstra changed his lineup for the fifth time, moving Joel Anthony into the starting lineup at center instead of Ronny Turiaf. The lineup favors defense, as Anthony is more athletic and versatile.

It had been a productive lineup during the postseason. Entering Game 4, the lineup of Anthony, James, Shane Battier, Wade and Mario Chalmers had outscored opponents by 35 points in 80 minutes during the playoffs.

Miami also rode forward Udonis Haslem's hot hand. Haslem missed a tough shot at the end of regulation, but he finished with 12 points and 17 rebounds in 36 minutes.

"As the series is getting tougher, more physical, it's not a coincidence that I'm increasing (Haslem's) minutes. Same thing with Joel," Spoelstra said.

However, the new starting lineup didn't matter. Rondo notarized the game early with his unique imprint in the first half. The Celtics jumped to a 21-6 lead with 5:17 left in the first quarter on 7-for-12 shooting on three-pointers.

The Heat have no answer for Rondo's ability to create for himself and others, mostly others. He delivered precision passes to cutters near the basket, and when Miami's defense collapsed on him, he found open shooters, many at the three-point line.

Six Celtics scored in double-figures: Pierce, Garnett (17), guard Ray Allen (16), Rondo (15), forward Brandon Bass (11) and guard Keyon Dooling (10).

But leads — even Boston's early 34-23 edge — meant nothing. Boston led 61-43 late in the first half, and 65-49 early in the third quarter.

"Our execution in the first half was flawless," Rivers said. "It was as good as maybe we've had, and we completely got away from it."

Miami's defense gets credit for that. The Heat increased the defensive intensity as they made a push to get back in the game.

"You have to collectively be willing to get into the pit and get your hands dirty for however many minutes it may be," Spoelstra said. "Often times, it won't necessarily be pretty. Both teams defend, both teams get after it and you have to find different ways to come out ahead."

Wade again started slow but finished with 20 points, 12 coming after halftime. Miami cut Boston's lead to 73-68 by the start of the fourth quarter and took the lead for the first time, 76-74, on guard Norris Cole's layup.

However, it was the second consecutive game in which the Heat were down big early. They trailed by 24 in Game 3, which Boston won 101-91.

"We waited until the second half, which we can't do," James said. "We can't wait until we get down and then make a big push."

Both teams had chances to win it in regulation and overtime. After James tied the game in regulation, Garnett was called for an offensive foul. Miami called a timeout and ran a play for James, but as he began his move to the basket, three Celtics defenders prevented James from getting into the lane. He passed to Haslem, who missed a shot at the buzzer.

Rondo outscored Miami 3-2 in overtime.

"Let's lean on our defense," Rivers said of his overtime game plan.

It worked. Miami was 1-for-8 in the final five minutes.

"No one said this was going to be easy," Spoelstra said.