It was a four-point game (46-42) six minutes into the second half, but Arkansas State's 11-point run -- with five from Reed and two treys from Johnson -- pushed the Red Wolves ahead 57-42 with 12:32 to go. The Muleriders were unable to get closer than 13 for the rest of the contest.
Reed finished with 19 points and Johnson scored 16 as Arkansas State finished on 27 of 56 shooting. The Red Wolves (7-4) racked up 29 points on free throws after shooting 88 percent from the line.
Southern Arkansas (4-4) got 44 of its points from the bench, with 17 coming from Jeffrey Walker and 16 from Chauncy Williams.
Arkansas State faces off in Sun Belt competition against Texas-Arlington on Thursday.
Forward Kennedy Meeks, who has averaged 9.4 points and 6.5 rebounds at North Carolina, has pulled out of the NBA draft and will return to the Tar Heels.
Cal big man Ivan Rabb could have been selected in the top 10 of the NBA draft. Instead, he's returning to Berkeley to make himself, and the Golden Bears, stronger.
Devin Williams' decision last month to sign with an agent and enter the NBA draft has left West Virginia in a tough spot.