MORGANTOWN, W.Va. -- All that strength work is paying dividends for Oklahoma's bruising Samaje Perine.

The 243-pound freshman almost matched his weight, rushing for 242 yards and four touchdowns to lead No. 4 Oklahoma to a 45-33 win over West Virginia in their Big 12 opener Saturday night.

Perine had three TDs in the second half as Oklahoma (4-0, 1-0) pulled away from a 24-24 halftime tie. He got the bulk of the carries in place of Keith Ford, who is out for at least a week with a hairline fracture in his right fibula.

Perine became the first Sooner to surpass 200 rushing yards since DeMarco Murray in 2010. Blake Bell was the last Oklahoma player to have four rushing TDs in a game against Texas in 2012.

"We did a good job of hitting the holes," said Perine, who averaged 7.1 yards on 34 carries. "Coach (Bob) Stoops told me that he had confidence that I could get the job done and I just went out there and did my best."

Perine was Oklahoma's No. 3 back entering the season. He's already built a reputation as a weight room beast, and his power showed against the Mountaineers.

"You know about how powerful and strong he is, but he has great vision," Stoops said. "He has great stamina and is a very conditioned athlete. He works hard at his conditioning."

Perine ran over two defenders and scored from 9 yards out early in the third quarter, then went up the middle for a 5-yard TD late in the quarter. His 19-yard scoring romp with 4:21 left in the game put Oklahoma ahead 45-27.

"He's tough," West Virginia linebacker Wes Tonkery said. "He's going to be something here to watch. He does what a running back is supposed to do."

Oklahoma won its eighth straight game dating to last season and its 11th road game in 12 tries.

Alex Ross scored on a 100-yard kickoff return and quarterback Trevor Knight caught a 4-yard scoring pass on a trick play for the Sooners.

Knight overcame a shaky start and finished 16-of-29 for 205 yards. Sterling Shepard caught six passes for 101 yards.

Knight was wide open when wide receiver Durron Neal found him in the end zone after taking the ball on a double reverse in the second quarter.

Clint Trickett threw for 376 yards and two touchdowns for West Virginia, (2-2, 0-1). But he was intercepted twice and lost a fumble.

Trickett went 25-of-41 a week after throwing for a career-high 511 yards a week ago against Maryland. Kevin White had 10 catches for 173 yards and a score while Mario Alford caught seven passes for 101 yards and a TD.

West Virginia outgained Oklahoma 513-500 but couldn't match Perine's power running. Rushel Shell had a team-high 60 yards and a touchdown.

"They played with more effort than we did in the second half," said West Virginia coach Dana Holgorsen. "They made good adjustments at halftime. They made a bunch of plays in the second half when the game was on the line. You've got to give them credit."

Knight had early accuracy trouble and Oklahoma punted on four of its first five possessions before finding a rhythm with a pair of 75-yard touchdown drives.

Alford, who dropped a pass in the left corner of the end zone in the second quarter, caught a 30-yard pass near the same spot on West Virginia's next drive that initially was ruled out of bounds. The play was overturned after a review and ruled a touchdown.

Perine and Shell traded short scoring runs before Ross went the length of the field on a kickoff return. It marked the third time in four games that the Mountaineers allowed a score just before halftime.