With United trailing 1-0 at the half, Moreno created a 1-1 tie in the 47th minute. Namoff's goal in the 56th gave United a 2-1 advantage and Emilio's goal in the 61st capped the rally.
The win pushed United (6-3-9) into a second-place tie with the Columbus Crew in the Eastern Conference.
Namoff recorded an own goal in the 14th minute for the lone score for the Rapids (6-5-6), who face the New York Red Bulls next Saturday.
2014: The Year in Fashion [PHOTOS]
UPI Sports Results for September 19, 2014