Aurimas Adomaitis led Long Island (2-4) with 17 points, and Kyle Johnson and Michael Culpo each added 14 -- with 12 of Culpo's coming on three-pointers. The Blackbirds shot 6-of-21 overall from beyond the arc.
Robert Morris made 8-of-16 three-pointers.
The Colonials (4-4) led at halftime, 39-27. Robert Morris has now won four straight over the Blackbirds.