AMES, Iowa -- Oklahoma didn't need star wide receiver Starling Shepard to rout struggling Iowa State on Saturday.

But the Sooners (No. 18 CFP, No. 19 AP) could definitely use Shepard next week against high-flying Baylor.

Oklahoma's Trevor Knight became the first FBS player this season to throw three TD passes and rush for three touchdowns in a game and the Sooners trounced Iowa State 59-14.

Knight had 230 yards passing, a career-high 146 yards rushing and six total scores for the Sooners (6-2, 3-2 Big 12). They gained a season-high 751 yards in beating the Cyclones for the 43rd time in their past 45 tries.

Knight did all that despite losing Shepard on Oklahoma's first play from scrimmage.

Shepard was carted off with a muscle strain in one of his legs -- coach Bob Stoops didn't specify which one -- and did not return.

Shepard has 50 catches for 957 yards and five touchdowns this season.

"I'm hopeful it's just a strain," Stoops said. "He was coming back to play, and I think it was already 21-7. And we said `Nah, let's try and rest him and be sure he'll be here next week. Now, I don't know whether he will be or not. We've got to wait and see."

Sam Richardson had 239 yards passing for Iowa State (2-6, 0-5).

The Cyclones must win their last four games to earn bowl eligibility.

The last time Iowa State beat Oklahoma in Ames was in 1960 -- three days before the presidential election between John F. Kennedy and Richard Nixon.

It didn't take long for the Sooners to turn this one into another landslide over the Cyclones.

Oklahoma opened with a 46-yard reception to Shepard, who quickly fell to the turf. Knight then corralled a bad snap and ran 31 yards untouched for a touchdown. The Sooners made it 14-0 on KJ Young's 16-yard TD reception.

Knight gave it back to the Cyclones with an interception at the Iowa State 4-yard line. But the Cyclones couldn't capitalize, and Blake Bell's 5-yard touchdown catch made it 21-0 late in the first quarter.

"It was one of those games we needed. Confidence-builder after three tough games there in October," Knight said. "It was what we needed, to come out and have a big time team win."

Iowa State did have a chance to make things interesting late in the first half.

Iowa State had Oklahoma fooled on a fake punt down 28-7, and defensive back Qujuan Floyd was wide open in Sooners territory.

But Floyd dropped the ball. Iowa State's fans let out a collective groan, and five plays later Knight ran for an 8-yard touchdown and a 35-7 lead.

"We're going to end up inside the 20 at the very least, if not score on the play. There was still enough momentum and life in us at that time," Iowa State coach Paul Rhoads said. "At 28-14 I would have been thrilled to see what we could have done."

But Iowa State simply couldn't stop Oklahoma on the ground.

The Sooners ran for 510 yards, their most since rushing for 518 against New Mexico State in 1989.

Alex Ross finished with 144 yards rushing and Samaje Perine had 110 with a touchdown.

Even Michael Hunnicutt got into the act with his 72nd field goal, surpassing the Big 12 record held by Colorado's Mason Crosby with a 44-yarder into a stiff wind.

More importantly, he showed he'd gotten over the mistakes that cost Oklahoma dearly in a 31-30 loss to Kansas State two weeks ago.

The same could be said for the rest of the Sooners, though that was hardly a surprise.

Oklahoma improved to 32-0 following a regular-season loss under coach Bob Stoops.

Now the Sooners finally get the Bears, a matchup that the Big 12 has been looking forward to since the summer.

"You feel like you've made some progress in how we executed. So, we've got to build on it and keep improving and hopefully get some guys back that are out," Stoops said.