Chris Young scored 23 points for South Alabama (0-2). He was 6-for-9 from the 3-point line. Michael Phillips added 13 points.
Mississippi State had a 48-36 advantage early in the second half when South Alabama scored 15 straight points to take a 51-48 lead with just over 10 minutes to play.
The Bulldogs went nearly eight minutes without a point during the run.
Mississippi State responded with an 8-2 spurt, capped by a three-point play by Roberts with 8:50 remaining to take a 56-53 lead. The Bulldogs did not trail again.
The Bulldogs shot 44 percent from the floor while holding the Jaguars to 40 percent shooting.
Mississippi State outrebounded the Jaguars 45-27, and the Bulldogs had 20 offensive rebounds.