The Cyclones (9-2) won despite a poor shooting performance from the field, hitting 36.7 percent of their shots. Christopherson and Garrett made just 12 of 32 shots from the floor and the backcourt duo converted on just 5 of 17 from 3-point range.
Jamie Vanderbeken was the only other Cyclone to reach double figures, scoring 14.
Iowa State jumped out to a 14-2 lead over the Tigers (1-7), but then struggled to maintain any momentum as Texas Southern went on a 21-10 run to pull within 24-23. The Cyclones then pulled to a 32-24 lead at halftime before eventually controlling most of the second half.