Milwaukee’s Malik Beasley knocks the ball from Boston’s Jayson Tatum during the first half  Tuesday at in Milwaukee. Morry Gash/Associated Press

MILWAUKEE  — Giannis Antetokounmpo left late in the third quarter with a calf injury, but the Milwaukee Bucks hung on to beat the Boston Celtics 104-91 on Tuesday night in a game that featured an NBA record-low total of two free-throw attempts.

Milwaukee snapped a four-game skid as Patrick Beverley had 20 points and 10 rebounds after the Bucks shook up their lineup by having the veteran guard start ahead of Malik Beasley, who came off the bench for the first time all season.

Antetokounmpo was heading up the court late in the third quarter after a Celtics basket when he grabbed his left calf and took a seat. The two-time MVP was helped off the floor, and cameras showed him heading to the locker room under his own power.

The Bucks said Antetokounmpo had a left soleus strain. The soleus is a muscle in the calf.

Antetokounmpo had 15 points, eight rebounds and seven assists, and he also attempted the game’s only free throws. He went 1 of 2 from the line in the first quarter.

Bucks Coach Doc Rivers said after the game that Antetokounmpo was undergoing an MRI on his calf and also would have his Achilles tendon tested. Rivers was asked about his concern level.

“High, I would say that,” Rivers said. “He’s Giannis. I think everyone probably feels the same way as I do right now. We’re just going to hope for the best.”

The Celtics became the first team in NBA history to go an entire game without attempting a free throw. The previous record for fewest combined attempts in a game was 11.

Milwaukee withstood Antetokounmpo’s injury thanks to a blazing start that enabled the Bucks to take a 24-point lead in the first half.

Brook Lopez and Bobby Portis scored 15 points apiece, and Damian Lillard and Khris Middleton added 12 apiece. Portis also had 10 rebounds.

The Celtics, who already have clinched the NBA’s best regular-season record and No. 1 overall playoff seed, were playing without Al Horford and Kristaps Porzingis. Horford was unavailable due to a sprained left big toe, and the Celtics are managing Porzingis’ workload after he missed five games last month with a sprained right hamstring.

“That was the first time where like the game wasn’t going our way since I don’t remember when, you know what I mean?” Celtics Coach Joe Mazzulla said. “To me, that’s a good opportunity, to play through that, find different ways to create runs, find different ways to just build stuff on either end of the floor. I thought it was a good situation for us to be in because we hadn’t seen it in a while.”

Jayson Tatum scored 22 points to lead the Celtics. Jaylen Brown had 14 points and 10 rebounds, and Jrue Holiday had 12 points.

Lopez went 4 of 5 on 3-point attempts in the opening six minutes to set the tone for a first quarter in which the Bucks shot 14 of 18 overall and 8 of 10 from 3-point range. The Bucks extended their lead to 47-23 on Portis’ dunk with 8:02 left in the second quarter.

The Bucks led 63-43 at halftime.

Antetokounmpo’s injury occurred during a 14-4 Celtics’ run that closed the third quarter and helped Boston cut Milwaukee’s lead to 78-67. The Bucks responded by scoring the first seven points of the fourth quarter, including five straight from Khris Middleton.

The Bucks stayed in front by double digits the rest of the way.