Troy (2-1) rebounded from last week's six-point loss at then-No. 2 Clemson. Kay hit from 42 yards early in the third quarter to break a 24-24 tie, and the Trojans extended the lead to 34-24 on Jordan Chunn's 39-yard run.
Nick Mullins closed the gap for Southern Miss (2-1) with a 16-yard TD pass to Allenzae Staggers late in the third. Mullins completed 24 of 52 passes for 263 yards and had the Golden Eagles at the 9 with three seconds left, but was unable to connect on the final play.
Ito Smith, 131 yards rushing, ended the first half and started the second with TDs, as Southern Miss rallied to tie at 24.