Avery Bradley added 14 points for the Celtics, who were nearly back at full strength in their final tuneup before opening the playoffs at Atlanta on Sunday.
Boston used its returning starters sparingly after pulling ahead by as much as 21 in the first half. The only starter missing was Ray Allen, who has been out the last two weeks with a sore right ankle.
Rondo, who had missed three straight with a sore lower back, had 12 assists in the first half, extending his streak to 24 games with at least 10 assists. It’s the longest streak in the NBA since John Stockton reached double-figure assists in 29 straight in 1992.
Kevin Garnett sat the last two games out to rest an injured hip flexor. He played 11:04 against the Bucks, all in the first half, and had four points, two rebounds and three assists. Mickael Pietrus returned after missing four games with a sore right knee and scored nine points.
Tobias Harris led Milwaukee with 17 points. Jon Leuer added 15 points and Brandon Jennings scored 12 for the Bucks, who were 28-28 on April 7 but never could return to .500, finishing the season at 31-35 with two straight losses.
Boston’s Ryan Hollins tied his career high with four blocks and scored nine points for Boston, which went up 2-0 on Pierce’s layup 17 seconds in and never let go of the lead.
Pierce scored the first five points of the game and had a dozen in the first half despite playing just 6:41. He left early in the first quarter with a sprained left big toe and the Celtics said he was unlikely to return. He returned for the end of the second quarter and scored five as Boston took a 60-42 lead into halftime.
Hollins scored seven points as Boston opened the second period on a 13-2 run and held Milwaukee without a field goal for the first 3:52.
Keyon Dooling started the scoring with a 3-pointer, and Hollis followed with a dunk, a three-point play after dunking an offensive rebound, and an 11-footer to put Boston up 31-20. E’Twaun Moore added a 3-pointer with 9:09 left in the period and Milwaukee called time out, down 34-20 after trailing by just three entering the quarter.
Notes: The Celtics won nine of their last 12 after a two-game losing streak in early April. … Boston C Greg Stiemsa missed his second straight game with a sore right foot. … Carlos Delfino (groin) and Monta Ellis (right hand) did not travel with the Bucks for the regular-season finale. … Bradley was the only Boston starter to score in the third quarter, finishing with eight points in the period.