McGruder finished with 22 points on 7-13 shooting, while Rodriguez had 20 for a Wildcats team that has now won four straight games.
Iowa State hung with Kansas State for most of the game, trailing by just one at the half. Then, with the Cyclones still within a point midway through the second half, the Wildcats went on a 12-3 run to create some distance. From there, Iowa State would get no closer than seven as Kansas State held off every comeback attempt.
Korie Lucious led Iowa State in the losing effort with 16 points and Tyrus McGee came off the bench to add 15 more. The Cyclones shot 12-27 from three as a team, but they were also hampered by 18 turnovers.
With the win, Kansas State avenges its Jan. 26 loss to the Cyclones, which was also the last time the Wildcats fell. They will look to make it five straight wins Monday night when they visit Allen Fieldhouse to face the reeling Kansas Jayhawks.