Diamond Miller and Ashley Owusu each scored 20 points to lead the Terps.
The defeat snapped the Terps' 10-game winning streak.
The Terps are giving up 75.9 points per game, the fourth-worst mark in the Big Ten.
Mimi Collins grabbed a career-high 17 rebounds to lead the Terps.
Diamond Miller had 23 points for the Terps, who extended their win streak to nine games.
Owusu and Miller scored 20 points each.
The Terps only used seven players in their Big Ten opener against Rutgers.
"I was able to do it all."
Owusu and Miller combined for 53 points against Towson, including eight three-pointers.