Reginald Johnson scored 15 points, including a pair of free throws with nine seconds left in regulation to force overtime, for Hampton (10-14, 6-5 Mid-Eastern).
Neither team scored in the extra frame until Johnson found Darden for a 3-pointer with 1:01 to play. After a stop on the other end, Darden hit two free throws to make it 69-64 20 seconds later.
James Carlton, who led Howard (12-12, 6-4) with 24 points, made a layup and, after a Hampton turnover, hit 1 of 2 free throws to pull the Bison within two with 29 seconds left.
Darden made two more free throws, and Quinton Chievous made 2 of 4 down the stretch, to seal the win.
Hampton shot just 34.5 percent from the field, but hit 11 of 24 3-pointers.