As the second half wore on, it became clear that Ohio State's defense would have to do the heavy lifting if the Buckeyes were to prevail against Penn State.

It was more than up to the task.

No. 3 Ohio State held No. 6 Penn State out of the end zone until the final minute, and its offense did just enough for a 20-12 victory in front of 105,506 at Ohio Stadium.

It was Ohio State's seventh consecutive victory against the Nittany Lions. Ryan Day has not lost to a Big Ten opponent other than Michigan in his five years as Buckeyes coach.

The game was befitting two of the top three defenses statistically in the country. Penn State's defense was ranked No. 1, but the Nittany Lions' schedule was so weak that Saturday would be its first real test. In that regard, it succeeded. The Buckeyes were stuck in mud most of the game, especially in the run game.

But Ohio State's defense was even better. Other than the 39- and 51-yard possessions that produced Penn State's field goals, the Buckeyes didn't allow more than 25 yards in any of the other 11 drives until the Nittany Lions scored its first touchdown with 29 seconds left.

“We started off stopping the run and forcing them to throw the football,” Day said. “You have to give (defensive coordinator Jim Knowles) and his staff a lot of credit for the adjustments made.”

They were even more dominant when the game was on the line in the second half. Penn State gained only 51 yards in its first six possessions and didn't get past the Ohio State 23-yard line until its final drive.

The Nittany Lions failed on its first 15 third downs. They finally decided to go for it on fourth-and-4 at their own 43 midway through the fourth quarter. Defensive J.T. Tuimoloau hit quarterback Drew Allar's arm as he threw and the ball fluttered harmlessly to the turf.

Ohio State's dormant offense, which was without injured running back TreVeyon Henderson and receiver Emeka Egbuka, finally cashed in. On third-and-12, Kyle McCord connected with Marvin Harrison Jr. for a 19-yard touchdown to all but seal the victory with 4:15 left.

“I think we targeted him 16 times, and he was open on most of those plays,” Day said of his junior receiver that had 11 catches for 162 yards. “He showed up in a big spot today again. I haven’t seen everybody play across the country, but it would be hard for me to find somebody who’s better in the country. I don’t know how he gets on these lists or doesn’t get on these lists, but to me he’s one of the most special players in the country.”

Penn State drove 73 yards to score on an 8-yard touchdown pass to Kaden Saunders with 29 seconds left. Its two-point conversion attempt failed, and Ohio State recovered the onside kick.

“It sucks to lose like this — especially on the road,” Allar said after completing 18 of 42 passes for just 191 yards. “(They’re) a really good team.”

Ohio State led 10-6 at halftime. The Buckeyes drove 57 yards to the Penn State 15 on its first drive before three straight incompletions forced the Buckeyes to settle for a 33-yard field goal.

Penn State's offense finally got untracked on its third possession when Nicholas Singleton started the drive with runs of 20 – its longest of the season – and 16 yards to the Ohio State 26. But the Buckeyes' defense stiffened, and Penn State kicked a tying field goal.

The biggest play of the half came with just over nine minutes left in the second quarter. Ohio State drove to the Penn State 26 when McCord was stripped of the ball. Penn State linebacker Curtis Jacobs scooped up the ball at the 40 and ran for an apparent touchdown. But cornerback Kalen King was called for holding Harrison on the play, wiping out the score and giving Ohio State a first down.

Harrison then made a tough catch to convert a third-and-10 and Miyan Williams punched it in from the 2 for the half's only touchdown.

Penn State answered with a field goal on the ensuing possession. Allar, who struggled all day (18 of 42 for 191 yards), completed a 34-yarder to tight end Theo Johnson to set up a 41-yard field goal that made it 10-6.

The Buckeyes couldn't capitalize on a 35-yard completion to Harrison to the Penn State 40 late in the half. Like Allar, McCord also had his struggles in the first half. He was 11 of 21 for 125 yards and was off-target on some potential completions.

Neither team scored in the third quarter. Ohio State drove to the Penn State 1 late in the period after a terrific 30-yard catch by tight end Cade Stover and a 5-yard run by quarterback Devin Brown, who was inserted when OSU got to the Penn State 6. But Brown was injured on the play. With McCord back at quarterback, he handed to Miyan Williams, who was swarmed in the backfield.

Day elected to go for it on fourth-and-goal from the 2. McCord threw to freshman Carnell Tate, but safety Zakee Wheatley tackled him for no gain.

Ohio State would kick a field goal on its next possession thanks to completions of 28 yards to Harrison and 29 to Stover.

McCord finished 22 of 35 for 286 yards.

Contributing: Rob Oller, Columbus Dispatch, The Associated Press