The win was all the more impressive in a game that never felt in danger of being lost despite the absence of Jayson Tatum.

The Celtics will play bigger, more consequential games during this playoff run, but Wednesday’s game quietly meant quite a bit.

BOSTON — Before the Orlando Magic left Florida to begin their first-round playoff matchup against the Boston Celtics, they felt they had learned valuable lessons last spring about the mental side of an NBA postseason series.