Gibbs was 10 of 18 from the floor and had six assists. Thomas made 9 of 19 field goal attempts.
Texas Southern (15-12, 12-2 Southwestern Athletic Conference), which has won seven of its last eight, led most of the game but could never break free of the Delta Devils. TSU led 70-60 with 7:36 remaining when Mississippi Valley State had a 9-3 run to close to 73-69 with 4:54 left, but the Tigers held MVSU to four points after that.
TSU remains tied atop the conference standings with Alabama State (16-7, 12-2), which beat Southern 56-54 on Monday night.
Jeffrey Simmons led MVSU (5-23, 4-11) with 25 points and DeAngelo Priar chipped in 12.