Miami Heat star Jimmy Butler certainly doesn't lack for motivation, but his competitive urges rose significantly in the middle of the fourth quarter on Friday.

Boston reserve Grant Williams started chirping after sinking a 3-pointer to give the Celtics a nine-point lead in Game 2 of the Eastern Conference finals.

Fifteen seconds later, Butler made a basket and the two players literally went eye to eye. Both players were assessed technical fouls.

Less than four minutes later, the hard-charging Butler made back-to-back shots, including the tiebreaking basket with 2:33 remaining, as Miami took a 2-0 series lead with a 111-105 victory.

Butler enjoyed his second straight stellar all-around game with 27 points, eight rebounds, six assists and three steals as Miami won in Boston for the second straight game to open the best-of-seven series.

Miami began an 18-4 run after the Williams 3-pointer, with Butler being the key man in the game-winning rally.

"He hit a big shot and started talking to me. I like that," Butler said. "It makes me key in a lot more, it pushes that will that I have to win a lot more and it makes me smile. I'm a decent player. ... I don't know that I'm the best person to talk to."

Said Miami forward Caleb Martin: "We'll take Mad Jimmy any time. I could see it in his eyes that he was ready to go after that."

Martin also excelled, establishing a career playoff high with 25 points on 11-of-16 shooting off the bench for the eighth-seeded Heat. Miami's Bam Adebayo contributed 22 points, 17 rebounds and nine assists, and reserve Duncan Robinson chipped in 15 points.

The Heat are now in position to win the series without coming back to Boston. Games 3 and 4 will be played in Miami on Sunday and Tuesday, respectively.

Jayson Tatum had 34 points, 13 rebounds and eight assists for second-seeded Boston but didn't convert a field goal in the fourth quarter for the second straight game. All five of Tatum's final-quarter points came on free throws in the final minute.

Jaylen Brown scored 16 points but shot just 7 of 23 from the field for the Celtics. Malcolm Brogdon and Robert Williams III had 13 points apiece.

Brown asserted that the series is not over.

"Both of these two games, they've been able to come out on top," Brown said. "But who's to say we can't come out on top the next two games? We just have to be ready to play basketball. We can't lose our confidence. It's first to four, and it will sure make for a better story."

The Heat connected on 45.7 percent of their shots and were 9 of 26 (34.6 percent) from behind the 3-point arc. Max Strus added 11 points for Miami.

Boston shot 46.8 percent from the field, including 10 of 35 (28.6 percent) from 3-point range. Derrick White had 11 points for the Celtics.

Robert Williams' dunk gave Boston a game-high, 12-point lead with 10:35 remaining in the contest.

Robinson responded with two 3-pointers during Miami's ensuing 10-2 spurt to cut the Celtics' lead to 91-87 with 8:40 left.

After Boston pushed its lead back to nine, the Heat scored nine of the next 11 points as part of the 18-4 run. Robinson's layup pulled Miami within 98-96 with 4:36 to play before Grant Williams scored on a dunk with 3:52 left for the Celtics.

Adebayo made two free throws and Butler added consecutive baskets, including the go-ahead hoop as Miami went up by two. Strus split two free throws and Adebayo slammed home a rim-rattling dunk to make it 105-100 with 55 seconds remaining.

Tatum scored his first points of the fourth quarter by making three free throws with 49.3 seconds left. Gabe Vincent knocked down a jumper with 35.1 seconds left to give the Heat a 107-103 edge.

After Tatum made two free throws with 21.6 seconds to go, Vincent and Strus each made two free throws to seal it for the Heat and to leave the Celtics seeking answers.

"We need to get together," Robert Williams said. "Time is running out. We don't have time for these mess-ups."

Tatum scored 15 points in the third quarter as Boston turned a four-point halftime deficit into an 83-75 lead. The Celtics outscored the Heat 33-21 during the period.

Martin had 14 points before halftime as the Heat held a 54-50 edge. Tatum scored 14 in the half for Boston.

--Field Level Media