United will have a chance to salvage its poor season by winning a trophy when it travels to Utah on Oct. 1 for the Open Cup final.
United, in the midst of a horrible league campaign, defeated the Chicago Fire 2-0 for its first road victory of the season, on the strength of goals from Dwayne De Rosario and Nick DeLeon.
RSL, meanwhile, defeated the Portland Timbers 2-1 at home as Alvaro Saborio, and Joao Plata provided the goals.
DCU has won the Open Cup twice in its history, first in 1996 and then again in 2008. RSL has never won the competition, and will be participating in its first Open Cup final.
The winner of the final will receive $250,000 in prize money as well as an automatic berth into the 2014-15 CONCACAF Champions League.