Watch: Tyrese Maxey beats the Celtics' shot clock

A shot clock violation would have given the 76ers the ball out of bounds. But because Maxey caught the ball in front of the referee and immediately bolted down court, there was no whistle. Even Maxey couldn't believe he was that open, glancing back just before laying the ball in.

"For the record, he got to the free throw line and turned backwards and almost stopped because he said he thought he heard a whistle," Sixers coach Doc Rivers said. "Which would've been nuts if that had happened. So I'm glad he laid it in. That's all I have to say."

Maxey finished with 26 points, but it was his defense that shone late. Especially since he was playing with five fouls. Before getting his steal, Maxey had guarded three different Celtics, doubling Jaylen Brown to get the ball out of his hands, then running both Marcus Smart and Jayson Tatum off the three-point line.

All that gave James Harden the chance to hit the game-winning three over Al Horford.

For the record, Harden had a full seven seconds left on the shot clock.