Corey Clement's 2-yard TD run staked Wisconsin to a 24-7 advantage early in the third, but the Tigers scored the final 21 points of the game.
Anthony Jennings, taking over under center for the graduated Zach Mettenberger, was 9-of-21 for 238 yards and a pair of TD passes. Hilliard carried the ball 18 times for 110 yards and Travin Dural caught three passes for 151 yards and a touchdown for LSU (1-0), which went 10-3 last season.
Melvin Gordon totaled 140 yards on the ground on 16 totes with a touchdown for the Badgers (0-1), who finished 9-4 a year ago. Former safety Tanner McEvoy was just 8-of-24 for 50 yards with two interceptions in his first career start in defeat.
Gordon ran the ball just three times in the second half.