The Catamounts (21-7, 12-3 America East Conference) have won 12 of their last 13 games and snapped UMBC's three-game winning streak.
The Retrievers (12-14, 6-8) led 37-30 at halftime and scored the first basket of the second half. The Catamounts responded with an 11-0 run, then built a 55-46 lead.
UMBC cut the deficit to three, but Vermont used an 8-0 spurt to pull away.
The Catamounts made 31 of 55 field goals (56.4 percent) while the Retrievers were 25 of 62 (40.3 percent).