The first-place Buffalo Bison fell behind 16-3 against Zimmerman on Tuesday evening but regrouped to defeat the Thunder 71-61 in Zimmerman.
The Bison still trailed 38-28 with 13 minutes left but outscored the Thunder 43-23 from then on, boosted by four double-digit scorers.
Zimmerman got 26 points from senior guard Brandon Giese, a recent 1,000-point club member.
Junior forward Caleb Ruter tallied 19 points, sophomore guard Ethan Freer 18, senior guard Andy Ormann 14, and senior center Kennan Brown 14 for Buffalo.
The Bison were patient on offense and took good care of the ball, forcing the Thunder, who love to run, to sit back on defense for long stretches. The Bison especially took away the Thunder fast break in the second half.
Blake Ehley and Gavin Doppler added 10 points each and Nate Christensen 8 for the Thunder, who dropped to 1-3 in conference and 8-4 overall.
Buffalo, with eight straight wins after an 0-3 start, is now 5-3 in conference and 8-3 overall. The other Mississippi 8 unbeaten is St. Michael-Albertville at 4-0.
Zimmerman will play at Big Lake on Friday evening.