Exclusive: Celtics star breaks history during debut.

The Boston Celtics blew out the Dallas Mavericks on Friday night. Jayson Tatum (32 points) took over the second half, Jaylen Brown (25 points) quietly dominated on both ends, and Kristaps Porzingis (24 points) was firing on all cylinders from the jump.

All of those guys have been putting up those numbers all season. It’s almost as if fans have become numb to their greatness. And on Friday, there was a shiny new object that stole a chunk of the attention.

But in this case, the shiny object could turn out to be gold.

Xavier Tillman played his first real minutes since joining the Celtics ahead of the trade deadline. He got some run in the second and fourth quarters, and though his box score totals won’t jump off the page, his performance certainly raised some eyebrows.

“X looked good out there, man,” said Jaylen Brown. “It’s like he fit right in. he came right in and made contributions on defense, got a few rebounds, got some stops. And then, on offense, you can tell he’s got a good feel for the game.

“A good screen-setter. He’s got big hands, so I was able to find him a few times on the baseline and hit him in some of those seam passes, and just reading the defense and how they’re guarding. X looked real good tonight.”

Tillman finished the night with six points, one rebound, two assists, and a block while shooting 3-of-3 from the field, but it was everything in between that jumped out.

Nearly every stat he recorded told a deeper story.

His first points of the game were a result of some impressive defense on Luka Doncic. Tillman stuck with the Mavericks star, forced him to swing the ball, and after a Jrue Holiday steal, he was rewarded with a transition bucket.

The 25-year-old big man had no idea he was going to play, but he was hustling from the moment he touched the floor. And though he wishes he would have finished off a nifty dime from Jayson Tatum, he was happy with his play overall.

“Definitely didn’t know. I had no clue,” Tillman said with a smile. “I definitely had no clue. I felt like the minutes went well. I feel like the minutes went well as far as offensively [and] defensively.