Bridge, who sat out the final quarter, finished with 362 total yards, just three shy of the school record.
Shavarez Smith was his main target as Smith pulled in six passes for 133 yards and two touchdowns.
South Alabama (3-2, 2-1 Sun Belt Conference) amassed 582 total yards.
Bridge ran in from the 8 for the first score. He connected with Smith on a 67-yard strike in the second quarter to push the lead to 20-0 after Grant McLaurin connected on two field goals.
USA scored three touchdowns in the third quarter for a dominating 40-7 lead.