Jayson Tatum scored 27 points and Marcus Smart electrified the Celtics with a superb all-around effort as Boston rolled to a 127-102 victory over the host Miami Heat on Thursday, evening the Eastern Conference finals at one win apiece.

Smart returned from a one-game absence caused by a foot injury and contributed 24 points, 12 assists, nine rebounds and three steals in 40 minutes. Smart also made five 3-pointers to help the Celtics avenge their Game 1 setback.

Jaylen Brown registered 24 points and eight rebounds and Grant Williams scored 19 points for Boston.

Jimmy Butler led the Heat with 29 points. Gabe Vincent and Victor Oladipo added 14 points apiece while Tyler Herro scored 11 for Miami.

Game 3 is Saturday night at Boston.

The Celtics were outscored 39-14 in the third quarter of Game 1 as an eight-point halftime lead turned into a 118-107 loss. They had no such troubles this time.

Boston led by 25 points at halftime and played the Heat to a standstill (26 points apiece) in the third quarter to take a 96-71 lead into the fourth quarter.

Smart buried a 3-pointer to push the lead to 103-73 with 9:55 left as the Celtics continued to roll. Boston's biggest lead was 34 points.

Al Horford (COVID-19 protocol) also returned for the Celtics after missing Game 1 and had 10 points on 4-of-4 shooting. Horford cleared the protocol hours before tipoff.

Miami lost P.J. Tucker to a left knee contusion in the third quarter. He had five points and four rebounds in 22 minutes before exiting.

The Heat were also without Kyle Lowry (left hamstring) for the eighth time in the past 10 games.

The Celtics shot 51.2 percent from the field, including 20 of 40 from 3-point range. Tatum and Brown each made four 3-pointers.

Miami connected on 44.2 percent of its shots and was 10 of 34 (29.4 percent) from behind the arc.

Boston made 12 of 19 3-point attempts (63.2 percent) in the first half while building a 70-45 halftime lead. The Celtics led by as many as 29 before the break.

Boston's onslaught occurred after it fell behind by 10 just 4 1/2 minutes into the game.

Brown drained a 3-pointer with 3:44 left in the first period to start a string of 17 straight points as the Celtics eventually took a 32-21 lead. Boston led 35-24 at the end of the quarter.

Williams' layup made it 68-39 with 1:16 remaining in the second quarter before Boston settled for the 25-point halftime cushion.