BOSTON -- The Miami Heat left Jayson Tatum lying on the court with a pain in his neck in the closing minutes of Game 3.
The Celtics All-Star did his part to make sure the Heat were hurting after Game 4.
Tatum scored 31 points and Boston took its turn pounding Miami early, jumping out to a 26-4 lead and cruising to a 102-82 victory that evened the NBA Eastern Conference finals at 2-2.
"Obviously, we knew how important this game was," Tatum said. "Everybody just had to come up with a different sense of urgency."
Miami missed 15 of its first 16 shots as this bizarre series produced another game that was all but over after 12 minutes. The Heat led 39-18 after the first quarter of Game 3.
Boston improved to 5-0 this postseason following a loss. Coach Ime Udoka said the challenge is finding more consistency.
"Just got to muster that same energy when we came off a win as well as a loss," Udoka said. "This is a three-game series now. Can't always just flip the mindset when we come off a loss and get a little desperate."
Game 5 is Wednesday in Miami.
Payton Pritchard had 14 points for the Celtics. Derrick White added 13 points, 8 rebounds and 6 assists, and Robert Williams finished with 12 points and nine rebounds.
"We just wanted to up the effort all-around," Williams said.
The Celtics led by 27 points in the second quarter and stretched their advantage to 32 in the third. Each game in this series has featured a lead of at least 20 points, and none has been close down the stretch.
Victor Oladipo led the Heat with 23 points. Miami's starting five of All-Star Jimmy Butler (six points), Kyle Lowry (three points), P.J. Tucker (no points), Max Strus (no points) and Bam Adebayo (nine points) were a combined 7 of 36 shooting. They all sat out the fourth quarter.
"They came out and jumped us," Heat Coach Erik Spoelstra said. "We're not making any excuses. They outplayed us tonight for sure. We never could get any kind of grip on the game."
And the Celtics stymied the Heat without Defensive Player of the Year Marcus Smart, who sat with a sprained right ankle he suffered in the second half of Game 3.
The Heat were without Tyler Herro, who suffered a groin injury late in Game 3.
Butler was in the starting lineup after missing the second half of Game 3 with swelling in his right knee. Lowry (strained left hamstring), Strus (strained hamstring) and Tucker (left knee irritation) all tested their injuries pregame before being cleared to go.
"It's a part of playoffs. You learn to adapt," Adebayo said. "Guys being out, guys playing half, guys playing 20 minutes in the game, just depends. You've just got to find a way to win."
Boston's Williams returned after missing a game with soreness in his surgically repaired left knee.
Even with their banged-up roster, the Celtics enjoyed their fastest start of the series. Starting in place of Smart, White scored the game's first seven points as Boston took an 8-0 lead.
It quickly grew to 18-1, with Miami misfiring on its first 14 shots. The Heat didn't get their first points until Adebayo's free throw at the 7:56 mark. Miami made its first field goal at 3:22, a three-pointer by Oladipo, and finished the quarter 3 for 20.
The Celtics took a 29-11 lead into the second quarter and led 57-33 at the half.
Per ESPN Stats & Info, the 18 points scored by Miami's starters is the lowest total by a starting five in a playoff game since starters were first tracked beginning in 1970-71.