A faster start. No more playing from behind.
USC came back to take the lead in the fourth quarter, but the Trojans could not hold on at Qualcomm Stadium.
Wisconsin drove for a go-ahead field goal, intercepted a pass by Cody Kessler and held off a last-minute drive to send the Trojans to a 23-21 defeat.
The loss left the Trojans with an 8-6 record in a season that began with Steve Sarkisian's embarrassing appearance at a booster event, included his firing five games into the season and eventually landed Helton the full-time job.
It also ended the careers of seniors from the 2011 and 2012 recruiting classes, who endured unprecedented tumult during their time at USC.
“Very sad for them,” Helton said of the seniors, “not the ending we wanted.”
Helton, who went 5-4 this season as interim and permanent coach, and the Trojans can now begin preparing for the 2016 season opener against Alabama. First, Helton must hire a defensive coordinator and several other assistants and make a recruiting push.
But Helton said it would not halt progress.
“I think you look at a bunch of young kids and a few seniors who won a Pac-12 South championship,” he said. “Our future is bright.”
USC would have moved toward that future with elation had the Trojans pulled out the victory.
USC got the ball with 39 seconds left in the game, time for one last chance at victory. But the drive ended at midfield after three Kessler passes fell incomplete.
Tailback Justin Davis rushed for two touchdowns and Kessler passed for one, but it was not enough against a Wisconsin team that got three field goals from Rafael Gaglianone and finished 10-3 under first-year Coach Paul Chryst.
Wisconsin quarterback Joel Stave completed 18 of 27 passes for 217 yards and a touchdown.
The Badgers outgained the Trojans, 394 yards to 286, in Helton's final game as USC's play-caller.
Wisconsin went into the game ranked first nationally in scoring defense and in the top six in rushing defense and pass defense. The Badgers held the Trojans to 65 yards rushing and pressured Kessler throughout the game. Linebacker Jack Cichy sacked Kessler on three consecutive plays in the fourth quarter.
“We knew it was going to be a physical game against a physical team,” Kessler said.
USC trailed 13-7 at halftime against a team with a playbook similar to Stanford's, if not the same talent.
Wisconsin then opened the second half with a drive that consumed more than six minutes and culminated with Stave's short touchdown pass to tight end Austin Traylor for a 20-7 lead.
The Trojans immediately answered, Kessler connecting with receiver JuJu Smith-Schuster along the right sideline for a 39-yard gain.
Receiver Jalen Greene scrambled for six yards on an option-pass play to set up Davis' four-yard touchdown run that pulled the Trojans to within seven points.
The Trojans forced Wisconsin to go three and out, but that only set the stage for a series of futility, as Cichy sacked Kessler on three consecutive plays.
“Once would have been great,” Cichy said. “Three times is just kind of luck of the draw.”
But USC's Greg Townsend Jr. sacked Stave on third down to force a punt, then Kessler completed a 17-yard pass to receiver Darreus Rogers, a 25-yard pass to tight end Tyler Petite and a third-down pass to Smith-Schuster.
That set the stage for a third-and-four play from the seven-yard line.
Kessler dropped back, rolled to his right and looked for a receiver in the end zone. He finally found Rogers for a seven-yard strike that put USC ahead, 21-20.
Wisconsin got the ball back with less than six minutes left and Stave drove the Badgers into USC territory, where Gaglianone kicked a 29-yard field goal.
USC got the ball back with 2:27 left, but the Badgers pressured Kessler and Sojourn Shelton intercepted his pass.