Derrick White put home Marcus Smart's missed three-pointer just before the final buzzer sounded to give the Boston Celtics a thrilling 104-103 victory over the Miami Heat to force Game 7 in the Eastern Conference finals.

After Jimmy Butler sank three free throws to give Miami a 103-102 lead with three seconds left, the Celtics inbounded to Smart, whose three-pointer rattled in and out.

But White grabbed the rebound and released it with 0.1 seconds on the clock to save Boston's season.

The Celtics are on the brink of the greatest comeback in NBA playoffs history, needing a win at home in Game 7 on Monday to become the first team to rally to win a series after losing the first three games.

Boston are only the fourth NBA team to erase a 3-0 deficit in a best-of-seven series to force a deciding game.

Monday's winner will face the Denver Nuggets in a title series that will start on June 1.

Jayson Tatum had 31 points and 10 rebounds, Jaylen Brown added 26 and 10 boards and Smart finished with 21 points as the Celtics improved to 5-0 when facing elimination this season.

Butler scored 12 of his 24 points in the fourth quarter to go with 11 rebounds and eight assists.

The Heat need a win Monday to become only the second number eight seed to make the NBA Finals and avoid the dubious distinction of being the first team to blow a 3-0 series lead.