​Lincoln Riley finally has a signature Big Ten victory at USC. And Ohio State’s College Football Playoff chances could be in real peril.The Trojans beat No. 2 Ohio State 30-18 on Saturday night in the Buckeyes’ first game without quarterback Julian Sayin, who suffered a potentially season-ending right shoulder injury in OSU’s win over No. 4 Indiana on Oct. 17.Trailing by 11 at halftime, Ohio State had a chance to get back into the game in the third quarter. But Luke Fahey’s pass to Isaiah West ended up as a fumble that was recovered by the Trojans after the Buckeyes had gotten into USC territory.Then USC freshman tight end Max Bowman went to work. The former five-star recruit and No. 44 recruit in the country broke off a 70-yard catch-and-run that included a hurdle and a bunch of broken tackles. Just watch as he sliced through the Ohio State defense like few players have been able to do.Two plays later, King Miller had given USC an 18-point lead. The game was over from there.Ohio State cut the lead to nine on a Jeremiah Smith TD catch with 2:12 to go, but the ensuing 2-point conversion failed when Fahey’s pass sailed out of the end zone.How real are USC’s playoff hopes?We’re not going to blame you if you’re still skeptical of the Trojans. This is a team that lost 24-7 at Wisconsin a week ago and had negative rushing yards. It’s also the same USC team that was dominated by an Oregon team that’s had a hard time getting its act together.But if you want to look on the bright side for USC … the playoff is a very real possibility. After an off week in Week 10, USC has trips against No. 4 Indiana and No. 7 UCLA remaining. If USC wins both of those games — and also beats Maryland — then it’s in the playoff. There will be no debate.USC’s offensive stats Saturday night were hardly eye-popping. But that’s also because the Trojans barely had the ball. Ohio State held onto the ball for two-thirds of the game and ran double the plays. USC had just 339 yards. But it also ran 49 plays.The victory is the first over a top-five team in Riley’s time in Los Angeles. If you’re still pessimistic about USC’s playoff chances, you were probably also wondering if Riley would be able to survive a loss on Saturday night to an Ohio State team with a true freshman quarterback making his first career start.That factor also can cloud the significance of the win. Even though Ohio State was favored by 6.5 points, it’s easy to see how this is a game that the Trojans should have won.And how real are Ohio State’s playoff hopes?Are the Buckeyes a playoff team without Sayin? Saturday night was the example of how they can easily end up missing the postseason without him.The Buckeyes have Oregon, Northwestern, Nebraska and Michigan remaining in the regular season. Ohio State will be favored in all four of those games, but they’re far from guaranteed wins. Especially if the Buckeyes’ defense plays the way it did on Saturday night. USC averaged nearly 7 yards a play before kneel downs