Gallinari netted 17 points to go with six rebounds and Kenneth Faried added 14 and 11 for the Nuggets, who improved to 10-1 at home and won for the third time in four games.
Blake Griffin donated 12 points and nine rebounds for Clippers, whose franchise-record winning streak ended with their first loss since Nov. 26.
Eric Bledsoe came off the bench to provide 12 points for Los Angeles, which hit only 38.5 percent of its shots from the floor.
Notable deaths of 2014 [PHOTOS]
UPI Sports Results for September 19, 2014