Athens Academy capitalized on two Commerce turnovers in the third quarter to secure a critical Region 8-A win.
The Spartans outscored the Tigers 21-10 despite the teams' near even offensive yardage.
Quarterback Cody Streetman, who twice left the game because of injury, scored Commerce's lone touchdown on a 1-yard run that made the score 12-7 by halftime.
Josh Swistak added a field goal at the beginning of the fourth quarter, Commerce's only score of the second half.
Commerce (3-4, 2-1) travels to Prince Avenue (7-0, 3-0) next week.