Justin Graham chipped in 10 for Hartford (13-13, 6-7 American East Conference).
Hartford led most of the second half but could never pull away from the Retrievers until Wroe drove for a layup to start a 7-1 run to go up 42-34 with 7:14 left. UMBC did not fold as Devarick Houston made two free throws to close to 54-52 with 11 seconds left.
The Retrievers (3-23, 1-23), who have lost 14 of their last 15 games, limited Hartford to 21-of-56 shooting from the floor but hit only 14 of 46 field goal attempts themselves.
Cody Joyce made 9 of 12 free throw attempts and had 17 points with nine rebounds for UMBC.