The Lady Eagles tied the game in the sixth on a Kayla Jennings home run.
The Lady Bison loaded the bases in the top of the eighth but worked out the inning with a line out and a 5-2-3 double play.
Cassidi Henderson (9-12) took the loss in both games.
OBU had four hits in the first game and six in the second with Ashley Clifton leading the way with three hits on the day.
OBU struck first again in the second game, getting an RBI single from Destinee Santistevan.
Now 21-27 on the season, the Lady Bison end the regular season with a makeup game at USAO Tuesday.