Blackman also tallied a game-high five assists to go with five rebounds and Cedric Smith grabbed nine rebounds for the Tigers, who outrebounded Western Illinois 33-26.
Savannah State (4-3) jumped out to a 22-13 halftime lead behind 11 first-half points from Hassan.
Western Illinois (3-3), following a 23.1 percent (6 of 26) first-half shooting performance, bounced back after intermission. The Leathernecks shot 50 percent (10 of 20) from the field and cut what was an 11-point second-half lead to one, 39-38, with 50 seconds remaining.
The Leathernecks held Savannah State scoreless over the final minute of the game but the Tigers' Arnold Louis blocked Don McAvoy's 3-point attempt as time expired.
Adam Link led Western Illinois with 11 points and had four of the Leathernecks' eight steals.