INDIANAPOLIS -- Trey Sermon ran for a school-record 331 yards and two second-half touchdowns Saturday, helping No. 4 Ohio State rally for a 22-10 victory over Northwestern for a fourth consecutive Big Ten championship.

The Buckeyes (6-0) will find out Sunday if they've done enough to earn one of four spots in the College Football Playoff. It's the first time Ohio State has won four consecutive outright conference crowns.

Northwestern (6-2) heads into the bowl season with two losses in its past three games and a second runner-up finish to the Buckeyes in three years.

After the Buckeyes settled for a field goal on the game's first possession, Northwestern running back Cam Porter answered with a 9-yard TD run late in the first quarter. The Buckeyes trailed from that moment until Sermon's 9-yard run with 2:41 left in the third quarter.

The Buckeyes had trailed for all of 5 minutes, 5 seconds this season -- until they fell behind for nearly 32 minutes Saturday.

Ohio State added a 26-yard field goal early in the fourth quarter, and Sermon, who had 29 carries, sealed the win with a 3-yard scoring run with 4:03 to go.

Ohio State quarterback Justin Fields was 12-of-27 with 114 yards and ran 12 times for 35 yards.

Fields told FOX Sports after the game that he believes he sprained the thumb on his throwing hand.

"I think it might be sprained," Fields said. "I'm not sure, I'll probably get an X-ray on it or something like that, but I was just trying to finish out the game."

Porter finished with 16 carries and 61 yards. Northwestern quarterback Peyton Ramsey was 24-of-37 with 224 yards but was picked off twice and lost a fumble -- all in the second half.

ESPN's Harry Lyles Jr. and The Associated Press contributed to this report.