Sophomore guard Thomas Dziagwa added 12 points with four 3-pointers for the Cowboys (1-0). Sophomore guard Brandon Averette and junior swingman Tavarius Shine scored 11 points apiece and senior guard Kendall Smith had 10.
Freshman guard Trae Berhow had 13 points and eight rebounds to lead Pepperdine (0-1). He was the lone player in double digits for a team that shot just 28.3 percent from the field and was 3 of 16 from 3-point range.
Oklahoma State led 34-21 at halftime and then got stingier defensively in the second half while making 56.7 percent of its shots from the field.
The Cowboys forced the Waves to miss their first nine shots in the second half. Sophomore forward Kameron Edwards finally got one to drop for Pepperdine with 11:23 left in the game to cut their deficit to 51-27.
Shine hit two free throws with 9:03 left to boost the lead to 60-30 and the Cowboys led comfortably the rest of the way.
Oklahoma State started the game by jumping out to a 13-4 lead. The Cowboys led by 11 after a 3-pointer by Dziagwa with 7:29 to go in the half before Pepperdine used a 9-4 push to move within four points.
The Cowboys closed the half with a 12-3 run for the 13-point halftime edge. The Waves were just 7 of 23 from the field in the half.