Mike Ladd added 11 points for Fresno State (15-17, 7-9 Western Athletic), which overcame a 10-point deficit early in the second half.
Jamel Guyton's 3-pointer with 1:02 remaining brought Louisiana Tech to within 61-59. Brandon Sperling and Smith combined to hit 5 of 6 free throws in the final 54 seconds and seal the victory for Fresno State.
Louisiana Tech concludes its conference play Saturday at Nevada in a game that will decide third place. Fresno State, meanwhile, moved a half-game ahead of San Jose State in the battle for fifth.