It wasn’t pretty. It wasn’t easy. And it sure wasn’t perfect. But thanks to an effective second half that allowed the team to pull away from Oregon State, the Cardinal kept its record unblemished and its national title hopes intact with a 38-13 win.

The No. 4 Cardinal (9-0, 7-0 Pac-12) came out flat on a cold, rainy day in Corvallis, Ore., struggling to find its offensive rhythm in the first half before eventually pulling away from the Beavers (2-7, 2-4) in the third quarter.

At the end of the day, redshirt junior quarterback Andrew Luck passed for another three touchdowns, and the Cardinal ended up with 507 total yards of offense—300 of them on the ground—but some offensive struggles left the Beavers still within shouting distance early in the second half.

Luck and the offense sputtered on their first two drives in the first quarter, with Luck tossing a sloppy interception on the second drive. But the Beavers failed to capitalize on Luck’s early struggles with two failed drives of their own, and the sluggish start led to a 0-0 tie after the first quarter, the only time this year the Cardinal has failed to score in the first quarter.

Things began to heat up offensively—and emotionally—in the second quarter, as senior running back Jeremy Stewart plunged into the end zone on the first play of the quarter to give the Cardinal a 7-0 lead.

After a three-and-out by the Beavers, Luck and company converted four third downs on the next series before a 17-yard fade to the end zone fell right into the hands of senior wideout Griff Whalen to make the score 14-0 in Stanford’s favor.

After Oregon State scored on its next drive to make it 14-7, Luck flipped a pass out to senior receiver Chris Owusu, who took a direct helmet-to-helmet hit from cornerback Jordan Poyer, collapsing Owusu to the ground in a heap.

The concussion-inducing hit would lead to Owusu being carted off the field in an ambulance—the third time this season the senior has taken a brutal shot to his hea, but the first that he was unable to walk off under his own power. Owusu was taken to the hospital but maintained a full range of motion and was able to return home with the team later.

The Cardinal was able to shake off the scary moment and drive down for a field goal to make the score 17-7 at half, but the Beavers came out of the locker room firing, engineering a quick scoring drive that made it 17-13 and set the Cardinal on upset alert for the second time in as many weeks.

After trading punts, the Stanford offense finally found its groove, scoring on its next two possessions with a pair of Luck touchdown passes to junior running back Stepfan Taylor and redshirt senior tight end Coby Fleener. At 31-13, Stanford had finally squashed the Beavers’ upset attempt, and junior running back Tyler Gaffney added another touchdown midway through the fourth quarter to round out the final margin of victory.

At the end of the day, Heisman frontrunner Luck would finish the day 20-for-30 through the air, tossing three touchdowns against one interception to give him 71 career passing touchdowns, just one behind Steve Stenstrom for second all-time in Stanford history and six behind John Elway’s record 77 touchdown passes.

Luck’s continued excellence didn’t overshadow a strong defensive effort, though, as the Cardinal defenders blocked both a field goal and an extra point, sacked quarterback Sean Mannion three times and held the Beavers to less than 300 yards of total offense.

Even though the victory was somewhat unspectacular, the win might have come at a very high price for the Cardinal, as the loss of Owusu was coupled with an injury to redshirt freshman tight end Levine Toilolo, who did not return to action after suffering a blow to the head in the second quarter.

Altogether, it means that the list of injured players continues to grow ever larger for the Cardinal, which was already missing starters at five positions before the contest with the Beavers.

Stanford will now have a week to get healthy and prepared for its colossal showdown this weekend against the No. 7 Oregon Ducks. After suffering an early loss to No. 1 LSU, the Ducks have reeled off eight straight wins and set the stage for Saturday’s contest to decide the de facto Pac-12 champion.

In a contest that has been anticipated since the schedule was released this spring, the Ducks will bring the nation’s fifth-best offense into Palo Alto hoping to upset the Cardinal and once again derail Stanford’s national-title hopes. In 2010, the Ducks were the only team to knock off the Cardinal with a 52-31 win in Eugene. Since that time, though, Stanford has held onto the nation’s longest win streak, which it extended to 17 games with the win over the Beavers.

The Cardinal returns to action this Saturday at home, welcoming ESPN’s College GameDay and the Oregon Ducks to town for a top-10 clash. Kickoff is scheduled for 5 p.m.