Most of the attention this week was on Luke Fahey's first career start, and I understand why, but Ohio State didn't lose this game because of the freshman quarterback.
The Buckeyes lost because their defense, the unit that had carried them through Iowa, Maryland and Indiana, got beaten up front all night.
For me, USC's offensive line against Ohio State's defensive front was the matchup that decided this game, and it wasn't particularly close.
USC came into Saturday off the worst offensive performance of Lincoln Riley's career, a 24-7 loss at Wisconsin where the Trojans ran for -17 yards and Jayden Maiava was sacked five times. A week later, against a defense that hadn't allowed 30 points in 31 games, USC looked like a completely different team.
The numbers tell the story. Maiava completed 15-of-22 passes for 222 yards and a touchdown, more than 10 yards per attempt. He had time to throw almost all of the night.
In the first half alone, he went 11-of-16 for 148 yards while Ohio State struggled to get any consistent pressure. That's been the defense's one real weakness all season, and USC exposed it.
The run game was just as frustrating. King Miller ran 13 times for 78 yards and a touchdown, and Waymond Jordan added 48 yards and another score on 12 carries. Combined, USC's backs averaged just over five yards a carry.
This was a run defense that had held Iowa to 39 rushing yards, Maryland to 82 and Indiana to 73. USC's line kept moving the line of scrimmage, and the Buckeyes' front couldn't get off blocks.
USC ran only 50 offensive plays, but they averaged 6.8 yards per play. Ohio State's offense ran 81 plays and outgained the Trojans 464-338, but the defense couldn't get off the field when it mattered and couldn't stop the big plays.
The tone was set 39 seconds into the game. On the second play from scrimmage, Maiava faked a handoff and threw a screen to freshman Trent Mosley, who went 69 yards untouched for a touchdown.
Simeon Caldwell couldn't get off his block, and Jaylen McClain took a bad angle. Before Saturday, Ohio State hadn't allowed a play longer than 36 yards all season.
Ohio State never recovered.
Later in the first quarter, Mosley returned a punt 44 yards. Two plays later, Jordan cut back through what felt like half the Ohio State defense for a nine yard touchdown and a 14-3 lead. Then, at the end of the first half, the team that usually wins the "middle eight" watched USC run a two-minute drill and kick a field goal for a 20-9 halftime lead.
The second half brought more of the same.
Tight end Mark Bowman caught a pass and hurdled McClain on a 70 yard gain down to the Ohio State 3, setting up another score. Missed tackles, blown assignments and bad angles kept giving USC free yards all day.
It wasn't just the defense. Ohio State committed 11 penalties, dropped passes, lost a fumble and failed to score from inside the one yard line before halftime.
USC beat the Buckeyes in all three phases, but the defense was supposed to be the steady piece while the offense adjusted to a freshman quarterback.
It simply wasn't.
This is the first time all season, and in awhile, that Ohio State's defense has been the reason they lost. That's what makes it so concerning, especially with Oregon coming to Columbus next Saturday.
The pass rush still isn't good enough. Ohio State has been able to cover for it when the run defense dominates and the secondary limits big plays. On Saturday, neither of those things happened, and USC's offense made the Buckeyes pay.
If Ohio State can't win at the line of scrimmage, their back seven will keep getting stressed, and good offenses will find the explosive plays this defense had avoided for most of the year.
The good news is that this defense has bounced back before.
After Illinois put up 462 yards in September, Ohio State responded with three of their best performances in years. Matt Patricia's group needs that same response now, because the reality is simple.
With a freshman quarterback, Ohio State's margin for error is small. The offense can't be expected to win a shootout. The defense has to be the best unit on the field, and on Saturday night in Los Angeles, it was a distant second to USC's offensive line.
USC came in with a plan to lean on their offensive line and make the Buckeyes' defense play in space. It worked from the very first snap all the way to the final whistle.
