Bam Adebayo was missing in action in the first two games of the Eastern Conference finals.

A bit of soul-searching and an upgrade in aggressiveness made a major difference in Game 3 as the Miami Heat center played one of the top games of his five-year career and repeatedly made demonstrative plays indicative of his first name -- Bam!

Adebayo exploded for 31 points, 10 rebounds, six assists and four steals on Saturday night to lead the Heat to a 109-103 victory over the host Boston Celtics.

"I had to pick up my weight," Adebayo said after the Heat took a 2-1 lead in the best-of-seven series. "These last couple games, my team was depending on me and I didn't show up. I took it upon myself to lock in and get the win."

Adebayo made 15 of 22 field-goal attempts after taking just 10 total shots over the first two games. Adebayo scored 10 points in Miami's Game 1 win and just six in its Game 2 loss.

"He's a winning player," Heat coach Erik Spoelstra said of Adebayo. "He really is the heart and soul of our group. You can count on him all the time. He doesn't get caught up in all the noise. He's just out there competing and playing winning basketball, doing it on both ends."

Adebayo's stellar performance was much-needed with Miami star Jimmy Butler missing the second half due to right knee inflammation. Butler scored eight points in 20 minutes.

Spoelstra said he didn't have an update but did indicate Butler won't need to undergo an MRI exam.

Jaylen Brown set a personal playoff high with 40 points and also collected nine rebounds for the Celtics, who committed 24 turnovers. Al Horford added 20 points and 14 rebounds but Jayson Tatum had just 10 points on 3-of-14 shooting and committed six turnovers.

"Unacceptable. I've got to play better," Tatum said of his performance. "I feel like I left the guys hanging tonight. That's on me."

Game 4 is Monday night in Boston.

The Celtics never led on Saturday and trailed by as many as 26 points early in the second quarter.

"We didn't match (their physicality) from the start," Boston coach Ime Udoka said. "We got into complaining and let it take us out of our game. It's disappointing to come out that flat in a conference finals game."

Still, the Celtics had a chance to post a comeback victory before the Heat held them off down the stretch.

Miami led by 13 with 6:30 left before Boston responded with 12 consecutive points. Brown scored 10 of them, including a 3-pointer that cut the Heat's lead to 93-92 with 2:40 to play.

Miami suddenly reawakened as Max Strus drained a 3-pointer, Adebayo hit a jumper and P.J. Tucker made two free throws to make it 100-92 with 1:07 left.

Boston was unable to get closer than six the rest of the way.

Tucker contributed 17 points and seven rebounds and Strus scored 16 points for the Heat, who shot 46.7 percent from the field, including 11 of 33 from 3-point range. Miami committed nine turnovers.

Kyle Lowry returned from a hamstring injury and recorded 11 points, six assists and four steals. Miami had 19 steals overall.

"We found a way," Lowry said. "Something about this team is that we have guys that are just hard workers."

Marcus Smart had 16 points and seven assists for Boston despite briefly leaving the game in the third quarter with a sprained right ankle.

The Celtics played without Robert Williams III (left knee). Tatum briefly left in the fourth quarter due to a right shoulder stinger.

Boston made 48.6 percent of its field-goal attempts, including 12 of 32 from behind the arc.

The Heat led by 15 when Butler was ruled out -- Victor Oladipo started the second half in his place -- and still led by that margin (87-72) when the third quarter concluded.

Adebayo scored 12 first-quarter points as Miami sprinted out to a 39-18 advantage. The Heat extended their lead to 46-20 on Caleb Martin's 3-pointer with 9:43 remaining in the half en route to a 62-47 lead at the break.

"We started out flat," Brown said. "Seemed like we were looking around too much instead of playing the game. We didn't match their intensity out of the gate."

--Field Level Media