Grant Wilson waited seven college seasons for a moment like this, and he made the most of it. Making his first start for No. 9 Indiana, Wilson threw two touchdown passes Saturday to lead the defending national champions past No. 18 USC 27-13 in Bloomington, a victory that kept the Hoosiers firmly in the College Football Playoff and Big Ten title chases.

Wilson, who played previously at Fordham and Old Dominion, returned for a seventh college season because he wanted to win a second national championship. "It's been a long time, seven years, and it's just such a blessing to be here with these fans and these players," he said.

Wilson replaced injured starter Josh Hoover at halftime two weeks ago and rallied the Hoosiers (9-1, 6-1 Big Ten) to an overtime win over Minnesota. Coach Curt Cignetti said he decided to start Wilson following that victory, and he stuck with him even though Hoover, who has been recovering from a right shoulder injury, was apparently healthy and available. Wilson finished 17 of 27 for 305 yards with one interception, and Cignetti did not say whether Wilson would remain the starter.

"Grant made some good plays, and he left some out there on the field," Cignetti said. "Now we'll figure out where we are and move forward."

The result was Indiana's first victory over a Top 25 opponent this season, and it came by two touchdowns with the team's No. 2 quarterback. That combination could help the Hoosiers solidify their postseason resume after they slid five spots in this week's playoff rankings.

Wilson wasted little time making an impression, connecting with Shazz Peterson on a 47-yard pass on Indiana's third play to set up his 13-yard touchdown toss to Brock Schott for a 7-0 lead. USC answered with a 29-yard field goal, and after the offenses bogged down, Indiana turned a Jayden Maiava interception into a 21-yard field goal. Maiava then capitalized on Wilson's interception, hitting Kayden Dixon-Wyatt for 51 yards before finding Zacharyus Williams for a 7-yard touchdown that tied the score at 10.

After the teams traded short field goals in the third quarter, Khobie Martin broke the tie with a 1-yard touchdown run with 2:39 left in the period, one play after a replay review denied him a 38-yard touchdown run and put the ball inside USC's 1. Charlie Becker added a 42-yard touchdown catch with 3:30 remaining to make it 27-13, and two late interceptions helped preserve the win.

Lee Beebe Jr. led the Hoosiers with 16 carries for 71 yards, while Martin finished with 10 carries for 70 yards to go along with the tiebreaking score.

USC (7-3, 4-3) needed a win to keep its playoff and Big Ten title hopes alive, but the Trojans managed only one touchdown in five red-zone trips. Maiava went 26 of 42 for 311 yards and one touchdown, but he was intercepted three times, twice in the fourth quarter, including once inside the Hoosiers' 5.

"He was a big part of us moving the ball the way we did, and the first interception he made a good decision on," USC coach Lincoln Riley said. "But the red-zone [interception], that one really hurt us." Trojans receiver Trent Mosley caught nine passes for 130 yards in the loss.