Boston got off to a quick start that had been overdue, and Jayson Tatum followed it with an NBA-first finish.
Tatum broke out for 51 points, the most ever in a Game 7, and the Celtics defeated the 76ers 112-88 on Sunday to advance to the Eastern Conference finals for the second consecutive season. Tatum had struggled in back-to-back games.
Tatum scored 25 points in the back-and-forth first half and another 17 in Boston's 33-10 third quarter, which turned a three-point lead into a comfortable lead.
Tatum had previously missed 14 of his first 15 shots before waking up in the fourth quarter to help his team save their season.
The Miami Heat and Boston Celtics will square off in the Eastern Conference finals for the second consecutive year. The Celtics lost to the Golden State Warriors in the NBA Finals last year. In Boston, the opening game is on Wednesday.
"I was happy to have another chance. After Game 6, our season might have ended, according to Tatum, who set the Game 7 record of 50 points two weeks ago with Stephen Curry.
"I had played as poorly as I possibly could for 43 minutes, and that was definitely on my mind.