The Heat were missing Shaquille O'Neal, Dwyane Wade and Alonzo Mourning, who all stayed in Florida to deal with injuries. Udonis Haslem and Antoine Walker spent the night on the bench.
Detroit had its regular lineup, other than unsigned Chris Webber, and dominated from beginning to end.
Richard Hamilton scored 11 for Detroit, including a perfect 9-for-9 from the free-throw line, while Rasheed Wallace and Antonio McDyess combined for 15 rebounds in 42 minutes.
Marcus Slaughter led Miami with 17 points and Brian Chase added 13.