The go-ahead score came after the Titans (2-1) took over on their own 6-yard line with 2:05 remaining and marched them 94 yards, capped by Locker's pass to Hunter in the front right corner of the end zone .
The key play on the drive came on 3rd-and-6 from the Chargers' 45 when Locker hooked up with Nate Washington for an 11-yard gain.
The Tennessee signal-caller completed 23-for-37 passes for 299 yards, adding 68 rushing yards with a score.
The Chargers (1-2) got a 19-of-23, 198-yard passing performance from Philip Rivers in the loss.
Antonio Gates made a TD grab among his five receptions for 55 yards.