Jayson Tatum’s key 3-pointer helps Boston pull away during Game 1 of the NBA Finals

After a massive first-half lead, the Celtics let Dallas put within eight points in the third quarter. Then Jayson Tatum and the Celtics put them away.

Former Duke basketball star [autotag]Jayson Tatum[/autotag] served up an early key moment during Game 1 of the NBA Finals during Boston’s 107-89 victory on Thursday.

The Celtics, thanks to a first-half explosion from Kristaps Porzingis, built a 21-point lead through two quarters. The Mavericks came out hot in the second half, however, closing within eight points with five minutes left in the third quarter.

Then, Boston slammed the door for good.

A 14-0 run for the Celtics lifted and separated the Eastern Conference champions once and for all, and Tatum buried a key basket for that run. After three free throws from teammate Jaylen Brown and a Porzingis dunk made it a 13-point lead again, the former Blue Devil put an exclamation point on the sprint.

Watch a video of his nails 3-pointer here.

Tatum finished the game with 16 points and 11 rebounds for the game, the only Celtics player to finish with a double-double.