The Wildcats (8-2) could never shake the Tigers (1-10), who trailed by just six points with 1:13 remaining. But four free throws in the final 35 seconds protected Kansas State's lead.
A 7-0 run by the Wildcats -- five of the points were by McGruder -- gave them a 46-36 lead with 15:03 remaining. It was the first double-digit advantage of the game.
The lead grew to 53-38 with 12 minutes to play. But Texas Southern went on a 10-2 spurt that included 3-pointers by Penn and Gibbs.
With 7:40 left, Texas Southern trailed 55-48 and hung in until the final minute.
ESPN's Dan Dakich joins The Paul Finebaum Show to discuss the SEC's presence in the NBA Draft.
Ted Kapita was the top-rated recruit from West Virginia in the class of 2015 and recently played at DME Academy in Florida.
With the Suns drafting Tyler Ulis, they now have five guards on their roster who attended Kentucky.