The Trappers rallied from a 16-point, third-quarter deficit to get the road win.
Jordan Suell scored 23 points, including a free throw with 14 seconds to play to tie the game.
The Trappers scored the first four points of overtime and never trailed the rest of the way.
“We were down 16. The wheels were off. But the kids never quit,” Fort coach James Ensley said. “They gave everything they had. Somehow we fought back into the game and ended up beating them.”
Will Doty added 14 points for Fort. Jacob Brugman had 10 points. Malachi King had seven steals.