Antetokounmpo made just 6-of-18 shots from the floor in the 105-89 setback Monday at American Airlines Arena. The Heat made 18-of-37 attempts from 3-point range (48.6 percent), led by Jae Crowder's five treys. Miami had five players with at least two made 3-pointers.
"The Heat are a team that plays hard for 48 minutes," Antetokounmpo said. "That's what they did. It wasn't just tough for me. It was tough for everybody."
The Bucks still own the best record in the NBA at 52-9.
Crowder and Jimmy Butler led the Heat with 18 points apiece. Bam Adebayo had 14 points, 13 rebounds, five assists and three blocks in the win. Butler also had seven assists and six rebounds. Brook Lopez led the Bucks with 21 points.
The score stayed close in the first quarter until the Heat's Kelly Olynyk caught fire. Olynyk scored eight consecutive points to spark a 9-0 run, giving Miami a 31-24 edge with 14 seconds remaining in the frame. The Heat took a 31-26 lead into the second quarter.
Crowder and Olynyk each splashed in 3-pointers to start the second frame. The Heat pushed their lead to 12 points before the Bucks fought back to tie the score at 40-40 with 6:24 remaining in the half. The Heat held on to a 53-52 edge at the break.
Antetokounmpo had just six points at halftime.
"Tonight there was a lot more focus, commitment and urgency because of the respect level for who we were playing," Heat coach Erik Spoelstra said of the Bucks.
The Heat used a 7-0 run to earn a 75-64 lead with 2:40 remaining in the third quarter. Miami held Milwaukee scoreless for nearly four minutes during the run. Heat guard Goran Dragic hit a 3-pointer at the buzzer to give Miami an 81-70 lead entering the fourth frame.
Milwaukee cut the Miami lead to seven points with 7:23 remaining before the Heat put the game away with a 10-0 run.
"That's how we want to play all the time," Butler said. "Unfortunately, we don't do that. Tonight could be what we look like [for the rest of the season]."
Antetokounmpo is averaging a career-high 29.6 points, 13.8 rebounds and 5.8 assists per game this season.