Brennan Amundson scored 24 points to lead the Battlers. Nick VanErp and Riley Leabo finished with 13 and 11 points, respectively.
Osakis was led by Daniel Savageau with 22 points. Brandon Boogard added 19 points and Luke Imdieke contributed a dozen.
Battle Lake (5-11) will play Brandon-Evansville in Evansville on Friday night.