Andrew Andrews netted 19 points for Washington (8-5), which has won four of its last five. Nigel Williams-Goss and Desmond Simmons each added 11 points.
For Hartford (5-9), Mark Nwakamma tallied 21 points while Nate Sikma tacked on 16 and Evan Cooper chipped in 15.
The Huskies clung to a 31-29 lead at halftime after shooting just 35.7 percent from the floor by holding the Hawks to just nine field goals, though six came from beyond the arc.
In the second half Hartford sank 65.2 percent of its attempts from the floor, while Washington hit on 58.8 percent. The Huskies managed to hold on by netting 19-of-22 attempts from the free-throw line.
Hartford had a 30-14 scoring advantage in the paint but had twice as many turnovers (14) as Washington (seven).