After defeating New England last week, the Black-and-Red have won back-to-back games for the first time since 2012
The home side got off to a great start and was ahead within four minutes. Bobby Boswell got a crucial flicked header off a corner kick and Arnaud was left open on the back post to head home from close range.
DCU continued to look threatening as the first half went on, but was unable to add to the lead before the half ended.
The Red Bulls started off the second half with much more enthusiasm, as Thierry Henry and Eric Alexander each went close, but neither could get the required accuracy on their shots, and DCU backup goalkeeper Andrew Dykstra did what was needed.
Peguy Luyindula then went closer still, but his close-range shot rattled off the outside of the near post after a giveaway by United in the midfield. The Red Bulls would come no closer on an extremely frustrating night for them.