BOSTON -- We expected Celtics-Nets to be an entertaining series, but Game 1 set a pretty high bar.
Tatum paced the Celtics with 31 points, eight assists, two blocks and a steal, while Jaylen Brown (23 points), Smart (20) and Al Horford (20) stepped up offensively as well.
Kyrie Irving nearly willed the Nets to victory with a game-high 39 points (and a "bird" to the TD Garden crowd), but Boston scored six of the game's final eight points to steal Game 1.
Here are our takeaways from a Sunday afternoon thriller at the Garden:
Tatum delivers when C's need it most
Tatum came into this series with something to prove against Durant and Irving, and he made quite the statement in Game 1.
The young All-Star was a force on offense, going 9 of 18 from the floor while dropping eight dimes, seven of which came in the first half.
While Tatum's buzzer-beating layup was the highlight, the 24-year-old made clutch shots throughout the game, including this 3-pointer that put Boston up 11 entering the fourth.
Meanwhile, Durant struggled mightily in the early going with just seven points on 2-of-10 shooting with four turnovers in the first half. Tatum played a role in Durant's early struggles, swiping KD on multiple occasions.
Durant found his shot in the second half, but Tatum clearly outplayed his USA Basketball teammate in Game 1, which is a great sign for the Celtics in this series.
Kyrie thrives in Boston spotlight
The Celtics had an 11-point lead entering the fourth quarter, but Irving erased it in a hurry.
The former C's guard scored or assisted on five of Brooklyn's first six buckets of the final frame, helping the Nets storm back to take a four-point lead with seven minutes remaining.
Irving scored 24 of his 39 points in the second half on 9 of 14 shooting, creating his own offense with Durant slumping offensively. His dagger 3-pointer with 45 seconds remaining put the Celtics' backs against the wall prior to Tatum's heroics.
Celtics fans booed Irving relentlessly throughout the game, but he clearly relished in the villain role, going back and forth with fans in the front run and hitting several clutch shots down the stretch.
That the Nets nearly won this game despite Durant's poor showing is a testament to Irving's offensive brilliance.
Smart, Horford provide secondary scoring boost
Jaylen Brown struggled to find his shot early with just eight points on 3-of-8 shooting at halftime. Fortunately for Boston, Smart and Horford both came to play.
Horford, whom Bruce Brown suggested Brooklyn should "attack" with Celtics big man Robert Williams sidelined, delivered an excellent all-around performance, hitting 8 of 13 shots while grabbing 15 rebounds (six offensive). Horford's sharpshooting helped the Celtics stay in the game early when shots weren't falling for Boston.
Meanwhile, Marcus Smart did Marcus Smart things, bringing the TD Garden to its feet by stealing an Irving inbound pass and converting the turnover into a slam early in the second half.
Smart then scored nine of Boston's next 12 points, hitting three straight 3-pointers to extend the Celtics' lead to double digits.
The longest-tenured Celtic stepped up on both ends in this one. He hit 4 of 9 3-pointers and also played tremendous defense to help keep Durant in check.
The Celtics are the deeper team in this series, and their depth was a big reason why they persevered in Game 1.
Boston and Brooklyn will get two days off before running it back Wednesday night at 7 p.m. ET at TD Garden. Coverage on NBC Sports Boston begins at 6 p.m.
Note: Games 2-6 of the Brooklyn Nets-Boston Celtics series will be aired exclusively on NBC Sports Boston and can also be streamed on NBCSportsBoston.com or with the MyTeams App, which you can download below.