Coming off a career-high 35-point outing in a loss at Texas on Tuesday, Anderson went 8-of-18 from the field, including 5-of-12 from 3-point range as Oklahoma State (15-9, 4-6 Big 12 Conference) finished 11-of-30 from behind the arc. Harris hit 4-of-8 from 3-point range.
Anderson also pulled down 10 rebounds for his first career-double-double as the Cowboys outrebounded Iowa State 37-27.
Craig Brackins led Iowa State (13-12, 2-8) with 27 points. Lucca Staiger added 14 points and Diante Garrett scored 12. It was the Cyclones' 13th consecutive Big 12 road loss and 15th straight loss in Stillwater.
Byron Eaton added 16 points for Oklahoma State.