Andrew Fitzgerald and Amath M’Baye each scored 12 points for Oklahoma and Je’Lon Hornbeak scored 10.
Oklahoma coach Lon Kruger’s second season in Norman got off to a slow start with the Sooners committing four turnovers in the first five minutes and missing six of seven shots.
Ten of the Warhawks’ first 12 points came off Oklahoma turnovers before the Sooners found their rhythm 10 minutes in when Cameron Clark found Tyler Neal for an alley-oop dunk.
Oklahoma stepped up its defensive pressure in the half’s final nine minutes, applying full-court pressure and trapping near halfcourt, and led 38-22 at halftime.
Oklahoma outscored Louisiana-Monroe 17-4 in the first five minutes of the second half. The Warhawks, who were 3-26 last season, were led by Amos Olatayo’s 21 points.