The Eagles (4-14, 1-2) capitalized on the Bulldogs (4-12, 0-3) sloppy play, draining 16 of 22 free throws off South Carolina State's 22 fouls and taking advantage of 15 Bulldog turnovers.
Coppin State shot 45 percent (27 of 60) and made 9 of 22 3-point attempts, guided by Armstrong's 4-of-11 showing from beyond the arc.
Matthew Hezekiah led South Carolina State with 23 points and nine rebounds, finishing a board shy of his sixth double-double of the year. The junior has finished in double figures in six straight, and was the only Bulldog with 10-plus points Monday.
Hezekiah hit 10 of 16 from the field, but his teammates made just 31.8 percent (14 of 44) from the floor.