Kyrie Irving added 24 points and seven assists for Boston, which avenged a loss to Milwaukee in Boston earlier this month.
The game was played at the UW-Milwaukee Panther Arena, formerly known as the MECCA, which served as the Bucks' home from 1968 until the team moved into the Bradley Center in 1988.
The Bucks chose to play one game this season at the 11,000-seat arena to mark the franchise's 50th anniversary. The team will move into a new arena next season.
Lauri Markkanen scored 11 of his 14 points in the second half, including a key 3-pointer with 48.