The Boston Celtics are the latest team unable to find an answer for Jimmy Butler and the Miami Heat.

The Heat, who initially looked outmatched at TD Garden on Wednesday night, rallied in the second half and held on to take Game 1 of the Eastern Conference finals. Butler put up 35 points and helped lead the Heat to a massive 46-point third-quarter performance before taking the 123-116 win in Boston.

After a tight first quarter, the Celtics finally surged ahead in the second after a massive 20-5 run in the middle of the period. That briefly gave Boston a 13-point lead, before it had to settle with a 9-point advantage at halftime. While the Heat shot nearly 54% from the field as a team in the first half, and were led by 15 points from Butler, they had 9 turnovers for 19 Celtics points.

Jayson Tatum also had 18 of his 30 points in the first half, and the Celtics took a huge 40-16 advantage in points scored in the paint. A lot of that came from center Robert Williams, who put up 12 points and didn’t miss a single shot from the lane in the first 24 minutes.

The Heat completely flipped the game around to start the second half, and tied things up almost instantly after opening the third on a 21-12 run while shooting 9-of-13 from the field. That left Celtics coach Joe Mazzulla livid.

Miami didn’t stop there. The Heat put up 46 points in the third quarter and outscored Boston by 21 in the period to suddenly take a 12-point lead, their largest of the game. They went 6-of-9 from behind the arc as a team and had just a single turnover in the period. It marked the highest-scoring playoff quarter in Heat history.

While Boston cut the game back to 5 points in the first 94 seconds of the fourth quarter, and held it there for most of the period, it was Caleb Martin who drilled a wide-open 3-pointer late before Butler followed suit with a wild bucket over Malcolm Brogdon that sealed the 7-point win.

Tatum led the Celtics with 30 points and 7 rebounds in the loss, though he had just 4 shot attempts in the second half and none in the fourth quarter. Jaylen Brown added 22 points and 9 rebounds, and Brogdon finished with 19 points off the bench. The Celtics, who narrowly got past the Philadelphia 76ers in their semifinals series after a 51-point performance from Tatum on Sunday, shot just 10-of-29 from the 3-point line as a team on Wednesday night.

Butler added 7 assists, 5 rebounds and a playoff-career-high 6 steals in the win for the Heat — who reached the conference finals after rolling past the New York Knicks 4-2. Bam Adebayo finished with 20 points and 8 rebounds. Miami shot just better than 54% from the field as a team, and went 16-of-31 from the 3-point line.

The Heat looked very solid in what was their sixth straight Game 1 win. They now hold the early advantage in a series many didn't expect them to contend in, especially considering where they started the postseason in the play-in tournament.

Game 2 of the series is set for Friday night. While there's still a long way to go in the conference finals, the Celtics don't want to be in a two-game hole before having to travel to Miami on Sunday.