The Celtics did not lead by more than 14 and appeared sluggish at times before improving to 5-0 for the first time since starting the 2009-10 campaign with six straight victories.
Tatum reached the 30-point mark for the fourth time this season and also reached 10,000 career points by converting a three-point play in the second quarter. At 25 years, 246 days old, Tatum became the youngest player in Celtics history to reach the 10K milestone.
Tatum made 10 of 20 shots, hit six of Boston’s 15 3-pointers and collected 11 rebounds. Jaylen Brown added 23 points while Kristaps Porzingis had his way inside against Brooklyn’s smaller lineup and contributed 22 to help the Celtics get 52 points in the paint.
Playing the second night of their first back-to-back, the Nets shot 43 percent and saw a three-game winning streak end. Cam Thomas led Brooklyn with 27 points while Spencer Dinwiddie and Mikal Bridges added 19 apiece.
Elsewhere, Joel Embiid supplied 26 points and 11 rebounds as hosts Philadelphia 76ers beat short-handed Phoenix Suns 112-100.
Kelly Oubre Jr. added 25 points, but Tyrese Maxey virtually put the game away, canning a pair of triples in a 1 1/2-minute span midway through the fourth quarter that ran the Sixers’ lead to 104-86. He finished with 22 points and 10 assists.
Kevin Durant netted a game-high 31 points for Phoenix, which was without star guards Devin Booker (ankle) and Bradley Beal (back).
Nikola Jokic had 28 points, 16 rebounds and nine assists, Michael Porter Jr. scored a season-high 27 points and NBA champions Nuggets defeated the Chicago Bulls 123-101 in Denver.