The playoff-bound Pacers won their fourth straight and stayed three games ahead of fourth-seeded Boston in the Eastern Conference.
They got 21 points and seven rebounds from Danny Granger in the victory.
Milwaukee's playoff hopes, meanwhile, took a hit despite 20 points from Monta Ellis.
With the loss, the Bucks dropped 2 1/2 games behind New York and Philadelphia in the race for the final playoff spots in the East.
Brandon Jennings added 16 points, 10 assists and eight rebounds in Milwaukee's setback.