NORMAN, Okla. (AP) - Even without Adrian Peterson , Oklahoma was able to run over Kansas State. The Sooners can only hope he'll be back in time to face Texas.

Peterson rushed for 51 yards and a touchdown before leaving with an ankle injury in the second quarter, putting a damper on Oklahoma's best offensive performance of the season and 43-21 victory over the Wildcats on Saturday night.

Kejuan Jones added two touchdown runs in relief of Peterson, and Rhett Bomar ran for one score and passed for another as Oklahoma (2-2, 1-0 Big 12 Conference) won its Big 12 opener for the sixth straight year.

''We never try to rely on one guy to win a ball game for us,'' Jones said. ''As running backs, we know anytime (Peterson) goes down, we've got to step our game up.''

Peterson, the Heisman runner-up last year, left the game late in the second quarter and sat on a table on the sidelines as trainers worked on his right foot. He tried to stand once, but took a seat again as trainers continued to examine him. At halftime, he walked off the field on his own, but was limping noticeably.

He returned to the sidelines in the second half, but did not play.

''He should be OK,'' Oklahoma coach Bob Stoops said. ''He could have played in the second half if we chose to. He had somewhat of an ankle injury. ... He had one a little earlier in the year and was able to play with it, and this is similar.''

The Sooners will face No. 2 Texas next Saturday in Dallas. Peterson had 225 rushing yards in last year's 12-0 win, Oklahoma's fifth straight win in the series.

''We feel that he should be able to go,'' Stoops said. ''It's just a matter of which day he is able to get back out there.''

Oklahoma, playing as an unranked team for the first time since 1999, was fine without Peterson against the Wildcats. The Sooners picked up 232 yards on the ground and held Kansas State to 22. It was the Wildcats' lowest rushing total since managing only one yard in last year's game against the Sooners.

Jones scored on a 3-yard run to give Oklahoma a 19-0 halftime lead, and the Sooners built on it with help from numerous mistakes by Kansas State (3-1, 0-1).

Freshman Reggie Smith 's first career interception set up an 8-yard touchdown run by Bomar on the Sooners' first possession of the second half and a 17-yard punt by Kansas State's Tim Reyer led to Jones' second touchdown run - a 2-yard plunge that made it 33-7.

At least that time Reyer was on the field.

In the first quarter, the Sooners grabbed a 9-0 lead when the Wildcats snapped the ball out of the back of the end zone on a punt attempt with Reyer still on the sidelines.

''I looked out and I saw it. I started on the headphones saying, 'The punter isn't in there,' and then I saw the ball. I thought, 'Thank goodness,''' Stoops said. ''We'll take anything we can get.''

On the Sooners' previous possession, they took advantage of a third-down personal foul by K-State linebacker Brandon Archer and took the lead on Peterson's 22-yard run.

Reyer's next punt attempt went only 8 yards after Jacob Gutierrez partially blocked it, and Garrett Hartley connected on a 29-yard field goal seven plays later to make it 12-0.

''We got our fannies waxed,'' Kansas State coach Bill Snyder said. ''We've just been doing all the things that can hurt us.''

Jordy Nelson scored on a 73-yard reception, and Rashaad Norwood had an 11-yard TD catch for Kansas State, which was trying to match its win total from last season.

Ayo Saba added a 1-yard TD run in the fourth quarter.

Asked to evaluate his offense, Snyder responded: ''Well, how do you want me to measure it? On a scale of one to 10, we were a zero.''

A loud boom could be heard from the stadium in the second quarter. Authorities later said one person was killed by an explosion believed to be a suicide in a traffic circle about 100 yards away from the stadium. There was no announcement made about the blast inside the stadium, but fans were instructed to avoid the area by a public address announcer.

Bomar had his first career touchdown pass on a 4-yard toss to Joe Jon Finley in the fourth quarter and finished with 139 yards on 12-for-22 passing and 67 yards on eight carries.

Allen Webb threw for 177 yards with two touchdowns and one interception for Kansas State.

Thomas Clayton , who was held out of last week's game after a campus incident involving a parking official, started and had only 8 yards on 12 carries. He had 329 rushing yards in the Wildcats' first two games.