Mavericks guard Klay Thompson drives to the basket as Celtics forward Jayson Tatum runs into a screen by Mavericks center Daniel Gafford on Thursday in Boston. Charles Krupa/Associated Press

BOSTON — The shorthanded Dallas Mavericks were in command from start to finish, handing the Boston Celtics one of their ugliest losses of the year, 127-120 on Thursday night at TD Garden.

Klay Thompson led six different Mavericks in double figures, scoring 23 of his team-high 25 points in the first half. Dallas played without new All-Star addition Anthony Davis (abdominal) but still feasted against the Celtics lethargic defense for most of the game. Dallas pushed its lead up to 27 points in the fourth quarter, leading Celtics coach Joe Mazzulla to pull his starters with 9:35 remaining.

Boston’s bench put up a bit of a fight in the fourth quarter, trimming the Mavericks’ lead from 27 to 10 with two minutes remaining before Dallas held off the late charge.

Jaylen Brown led five different Celtics players in double figures with 25 points while Jayson Tatum added 17 points. Boston allowed Dallas to shoot 55 percent from the field and dropped to 16-10 on the season at home.

Here are four takeaways from the Celtics’ loss on Thursday night:

Klay Thompson turns back the clock

The former Warriors star been underwhelming in his first year in Dallas but he looked like he was back in his prime against the Celtics. Thompson shot 10 of 13 from the field in the first half, knocking down a mix of midrange and 3-point shots. He did it in just 15 minutes and helped Dallas lead by as much as 18 in the first half.

Celtics defense delivers a no-show

On the heels of one of their better defensive efforts of the season against the Cavaliers on Tuesday, Boston looked like a team ready for the All-Star break. Dallas found easy looks in the paint and from the midrange with no pressure from the Celtics. Jrue Holiday’s presence (he was out with shoulder injury) may have helped but this was an underwhelming effort after it looked like the Celtics turned the corner winning four straight.

Celtics home woes continue

The Celtics have a habit of letting down at home which is a bit worrisome at this point. Boston fell to 16-10 with its loss Thursday, after going 37-4 last season. In fact, Boston’s home record is the worst among the NBA’s top 10 teams.

Good timing for Torrey Craig signing

The Celtics have been leaning heavily on their star wings for weeks now and the wear and tear looked apparent on Thursday. Jayson Tatum (four turnovers) and Jaylen Brown (three turnovers) struggled on both ends of the floor. Craig, a 34-year-old small forward who played in nine games for Chicago this season, won’t move the needle much, but is capable of playing off the bench. That should help the Celtics give Tatum or Brown some rest.