Rookie Tyler Herro scored a career-high 37 points, Jimmy Butler added 24 and the Heat held off the Boston Celtics 112-109 in Game 4 of the Eastern Conference finals Wednesday night near Orlando, moving Miami within one win of an NBA Finals berth.

Herro, 20, made 14 of 21 shots off the bench to continue his dynamic playoff run as the Heat grabbed a 3-1 advantage in the best-of-seven series. Goran Dragic had 22 points, and Bam Adebayo added 20 points and 12 rebounds.

"Just trying to get a rhythm going early," said Herro, whose 37 points are the second most in a playoff game for a player 20 or younger (Magic Johnson, 42). "Once you see a couple shots go down, the rest of the game is easier for you. Tonight was definitely a good night."

Jayson Tatum led the Celtics with 28 points, all coming in the second half, and Jaylen Brown had 21. Kemba Walker scored 20, Gordon Hayward 14 and Marcus Smart had 10 points and 11 assists.

Miami will get the chance to close out the series in Game 5 on Friday.

Unlike in each of the first three games, when the Heat fell behind by double digits, Miami opened up a 58-46 lead early in the third quarter. Prior to that run, the Heat's largest lead of the series was eight. Tatum, scoreless on six shots in the first half, came to life with 16 points in the period as the Celtics got within 77-76 entering the fourth.

"I wasn't aggressive enough," said Tatum of his slow start. "I had to play better."

Boston surged ahead for the first time since 11:05 of the second quarter on a Daniel Theis dunk with 8:51 to go in the game. An Adebayo basket and five points from Herro to reach 30 on the night put Miami up 91-85.

"Not too many people get an opportunity to make it this far in the playoffs and be in a game like this, but for him it's another day in the office," said Butler of Herro. "... He's been doing it all year long. To him, there's no pressure or anything. He's just going to keep playing basketball the right way."

The Heat upped their advantage to 98-90 on Herro's fifth 3-pointer with 4:09 left. Brown hit a trey and Smart added a layup to get the Celtics within three, but Dragic and Butler each made short buckets to reset the margin to seven.

After Tatum hit a trey, Dragic responded from deep and Herro added a layup to put Miami up by nine with 56.2 seconds remaining. Boston got within three again on a Brown 3-pointer with 16 seconds to go, but free throws by Herro and Butler helped Miami hold on.

Hayward hit a pair of free throws to tie the score at 40 with 3:38 left in the first half. The Heat responded with a 10-4 run to lead 50-44 at the break.

The Celtics committed 11 of their 19 turnovers in the first half.

"We've got to do a better job of handling the ball and taking care of it," said coach Brad Stevens.

--Field Level Media