It was the first league loss for Spring Lake after starting the league slate with three straight victories.
The Crusader surge in the opening half was highlighted by 10 made 3-pointers. For the night, Unity made 15-of-27 shots from behind the arc.
Spring Lake was led by Eli Morrison with 14 points, Zane Stahl with 13 and Zach Schlepp with 10.
Spring Lake (5-3, 3-1) will host Hamilton on Friday evening.