The Retrievers led, 38-34 at halftime, but hit only 12 of 36 shots from the floor in the second half. Rider took the lead for good on Harris Mansell's three-point field goal with 5:41 remaining to give the hosts a 58-55 lead.
Rider led, 66-63, in the final minute but UMBC had a chance to tie the game down the stretch after Proctor rebounded the miss of a jump shot. He drove down the floor, but had the ball stolen from behind with 48 seconds remaining and Rider's Novar Gadson hit two free throws after Greene committed a foul. After another UMBC missed shot, Mansell sealed the win with two free throws to put Rider ahead, 70-63 with 28 seconds remaining.
UMBC had won 21 straight games when leading at intermission, but dropped two straight this week.