Boston Celtics take down undefeated Cavaliers in a thriller, Tatum puts up 33 points
The Celtics unleashed a barrage of 22 three-pointers to overwhelm Cleveland, who clawed their way back to within two points of the lead late in the game after trailing by 21 early in the second half.
But despite the Cleveland fightback, reigning NBA champions Boston held their nerve and kept the scoreboard ticking over to close out a deserved win.
Tatum's 33 points included six three-pointers while the Boston star added 12 rebounds and seven assists in an all-round Celtics effort that saw six players finish in double figures.
Tatum said Boston's championship pedigree had helped the Celtics over the line as Cleveland started to threaten their lead.
"We've played a lot of basketball, we've played in the biggest games," Tatum said. "NBA is a bunch of talented teams - guys are gonna make plays, they're gonna make shots."
"I say it all the time - how you respond shows your growth and how special your team is."
Tatum admitted that ending Cleveland's unbeaten record, which has left them sitting on top of the Eastern Conference, had motivated the Celtics.
"They came in 15-0 feeling like they were the best team; we felt like we were the best team -- it's all competition. We were ready to play today," Tatum said.
Boston was quickly into their stride, rattling in five early three-pointers to sprint into an 18-8 in the opening minutes of the first quarter.
Cleveland rallied to reduce the deficit to 26-20 at the end of the first quarter, but the Celtics kept up the pressure in the second.
Tatum drained a superb three-pointer in the final seconds of the first half to give Boston a commanding 65-48 lead at the break.
The Celtics stretched into a 21-point lead early in the second half, but the Cavaliers clicked into gear and came roaring back to close the gap to two points at 88-86.
Tatum though had the last word, nailing an imperious three-pointer to give Boston a five-point lead heading into the final quarter. A nip-and-tuck final period saw Cleveland repeatedly close to two points but Boston pulled clear in the final minutes to seal victory.
Donovan Mitchell led Cleveland's scoring with 35 points while Evan Mobley added 22 with 11 rebounds and six assists.