Detroit led 78-71 going into the fourth quarter after leading 72-58 on Monroe's jumper with 4:14 left in the third.
The Pistons jumped out to an early 13-0 lead, holding the Bucks scoreless until 8:07 remained in the first quarter when Ellis made a driving layup. Milwaukee battled back to 19-17 on Ellis' two free throws with 4:03 left in the first and 21-19 with 3:02 remaining on a driving layup by Ellis.
Detroit then outscored Milwaukee 9-4 over the remainder of the quarter for a 30-23 lead after one. The Pistons led 55-45 at halftime after leading by as many as 14 twice during the second quarter.
Detroit made 57 percent of its shots and had 36 points in the paint in the first half.
"It was more than a bad start, it was a bad 3½ quarters," Milwaukee coach Scott Skiles said. "They outplayed us except for maybe six to eight minutes the whole game."
NOTES: Sunday was the 22nd anniversary of Skiles setting the NBA record of 30 assists in a game for the Orlando Magic. "The game is different now. It would be hard for someone to do it," he said. "Our team at that time wasn't that good, so it was an individual thing." ... Detroit G Rodney Stuckey didn't play because of a left ankle sprain. ... Sheila E. performed at halftime. ... Mbah a Moute left early in the first quarter with a cut on his lip. He received three stitches and returned late in the period.