Kurt Thorner scored three minutes into overtime, handing the host Waterloo Warriors a 4-3 win over the Lakehead Thunderwolves on Friday.
Thomas Cardiff tied the game with under four minutes to go, erasing a 3-2 Lakehead lead. Despite the loss the Wolves maintained their grip on third place in the OUA West, a point ahead of Brock, and two up on Guelph and Waterloo.
The Wolves could slip as far as fifth place, but must lose in regulation for the scenario to play out.
Victor Anilane, Jordan Smith and Jadran Beljo scored for Lakehead, while Josh Schappert and Tyler Moir also scored for Guelph.
The Thunderwolves (15-9-3) and Warriors (15-11-1) will end the OUA regular season on Sunday.