Maine (4-5) scored the first seven points of the game and led 38-24 at halftime after a 3 from Mitchell for the final points of the half.
Mitchell was 5 of 7 from behind the arc and scored all of his points in only 14 minutes on the court. Gerald McLemore added 12 points on four 3s.
The Black Bears were 27 of 50 from the field (54 percent), including 10 for 22 from 3-point range (45.5 percent).
Kyle O’Quinn and Pendarvis Williams scored 11 points each for the Spartans. Rob Hampton added 10 points and O’Quinn grabbed a game-high 11 rebounds.
Norfolk State shot 29.6 percent from the floor in the second half (8 for 27) and was outscored 28-14 in the paint overall.
The Spartans (1-7) trailed by as many as 27, 66-39, with 4:48 left to play en route to their sixth straight loss.