Jayson Tatum converted a last-second Marcus Smart assist into a buzzer-beating layup Sunday afternoon, giving the Boston Celtics a dramatic 115-114 victory over the visiting Brooklyn Nets in Game 1 of their Eastern Conference first-round playoff series.

With the Nets up 114-113 and looking for a clinching basket, Kevin Durant misfired on a 3-pointer with 15.0 seconds remaining, giving Smart and Tatum a chance to share the heroics.

Al Horford secured the rebound, and after Jaylen Brown found Smart wide open on the left side, the veteran guard passed on the shot and threw across the key to Tatum, whose catch-and-shoot game-winner had to survive a video review.

Tatum finished with a team-high 31 points, Brown had 23, and Smart and Horford scored 20 apiece in a balanced attack that allowed the Celtics to retain the home-court advantage in the best-of-seven that they earned by virtue of being the second seed in the East.

Kyrie Irving had a game-high 39 points for the seventh-seeded Nets, including a tie-breaking 3-pointer with 45.9 seconds remaining that gave the visitors a 114-111 lead. But Brooklyn never scored again.

Brown got the Celtics within one with a driving layup with 38.9 seconds to go, setting the stage for Durant's miss and Tatum's game-winner.

After the teams played on even terms through 25 minutes, Tatum ignited a 9-0 Celtics run with a bucket and Smart capped it with a dunk and a 3-pointer, the latter pushing Boston to a 72-63 lead.

The Celtics went on to lead by as many as 15 before the Nets chipped away, eventually going in front 100-98 on a Durant 3-pointer with 8:04 left in the game.

Brooklyn was up 107-102 before Boston drew even on a Smart layup with 3:16 remaining, setting up the tight finish.

Tatum also found time for a team-high eight assists and Horford completed a double-double with a game-high 15 rebounds for the Celtics, who will host Game 2 on Wednesday.

Irving's 39 points were three fewer than his postseason career-high, set against the Celtics in the 2017 Eastern Conference Finals.

Durant finished with 23 points, while Goran Dragic had 14 points and Nic Claxton added 13 points to complement a team-high eight rebounds for the Nets, who outshot the Celtics 53.8 percent to 47.2 percent.

--Field Level Media