Franks finished with a career-high 284 yards but it took a Germod Williams final-minute interception for the Bobcats (3-2, 1-0) to win their Sun Belt opener against Idaho (0-5, 0-3).
Idaho opened the game with an Austin Rehkow 29-yard field goal, and then forced turnovers on Texas State's first two drives. But the Vandals couldn't score, Rehkow missing twice. Franks was off to the races with lightning runs of 70 and a school-record 96 yards, going up 21-3.
After halftime, punter Rehkow recovered a Bobcats fumble, leading to one TD and later pinned the Bobcats at the 1, helping Idaho score again to trail 21-16. Idaho closed to 35-30 with 3:00 left, and Matt Linehan, despite eight sacks, passed for 347 yards and was driving until the Williams pick.