The Heat lost their third in a row, all of the setbacks coming on the road.
Denver held a five-point lead to open the fourth quarter and then scored the first nine points of the period. The Nuggets overcame a 35-point effort from LeBron James to win for the sixth time in seven home games.
James hit 13-of-20 from the field, but the rest of the Miami roster hit only 40 percent. Chris Bosh had 17 for the Heat.
Miami won its first five games of the season and eight of its first nine, but has fallen out of first place in the Southeast Division, a half game behind Orlando. There are four teams in the Eastern Conference with a better record than Miami.