It wasn't easy. The Heat battled back from a large 17-point deficit and had a chance to put the series away as they trailed by two points, only to have star Jimmy Butler miss on a 3-pointer with 20 seconds left in the game.
Celtics forward Jayson Tatum was voted the Larry Bird ECF MVP, and it was a big win for Head Coach Ime Udoka, who goes to the Finals in his first year coaching the team. He's the first rookie coach to ever win two Game 7s in the playoffs.
The Celtics hung on by their fingertips to eventually win it, 100-96. They'll now face the Golden State Warriors in the NBA Finals, Game 1 is on Thursday in San Francisco.
It's the first time the C's have made it to the Finals since 2010 — they haven't won a championship in 14 years. The Celtics are hoping to win their 18th title as a franchise — they're tied with the Lakers at 17 apiece right now.