The Nets are 2 ½ games behind Chicago for the final playoff berth in the Eastern Conference.
Miami dropped its third in a row after winning five out of six. Dwyane Wade, returning from a one-game absence brought on by a hip flexor, scored 27 points with eight rebounds.
After Miami rallied from a 12-point halftime deficit to tie the contest at 73-73, New Jersey went on a nine-point run. Douglas-Roberts hit a 3-pointer with 1:10 to play that boosted the Nets in front by eight.