AMES, Iowa -- Baker Mayfield threw four more touchdown passes for the streaking Oklahoma Sooners.

Mayfield completed 25 of 34 passes for 328 yards and 14th-ranked Oklahoma held off Iowa State 34-24 on Thursday night for its sixth straight victory.

Dede Westbrook caught seven passes for 131 yards and a score for the Sooners (7-2, 6-0 Big 12; No. 12 AP). They beat the Cyclones (1-8, 0-6) for the 18th time in a row and the 74th time in 81 meetings.

Mayfield threw TD passes to Westbrook and Dimitri Flowers in the final 4:16 of the first half, extending his streak of games with at least four touchdown tosses to an FBS-high four games.

Mayfield has 31 scoring passes, good for second nationally, with just six interceptions.

"That was a big jolt. They didn't have the lead but for 10 seconds," Oklahoma coach Bob Stoops said about the 65-yard TD reception by Westbrook that came immediately after Iowa State jumped ahead 17-14. "Dede and Baker have been doing that a bunch."

Oklahoma's defense stiffened after some early struggles, allowing just seven points in the second half to help the injury-depleted Sooners survive on the road.

"We're short a few guys. But we had some young guys step in and take full control of the game," Westbrook said.

Jacob Park passed for 160 yards and two touchdowns for the Cyclones in his first career start. They've dropped five straight.

Iowa State played without rushing leader Mike Warren. He sprained an ankle last week in a loss to Kansas State.

"I just think knowing that the front we were going to face, we had to throw the football a little bit, and you Jacob gave us the best opportunity to start the football game," Iowa State coach Matt Campbell said.

THE TAKEAWAY

Oklahoma: The Sooners maintained their hold atop the Big 12 by avoiding the Thursday night road upset that has derailed more than a few teams in recent years. With Baylor, West Virginia and Oklahoma State up next, Oklahoma is control of its own destiny in the league title race.

Iowa State: The Cyclones showed glimpses of promise yet again. But they're not ready to beat a conference contender like Oklahoma quite yet. Still, it was the fourth time in six games that Iowa State was within 10 points in a league game.

POLL IMPLICATIONS

Oklahoma didn't do much to impress the voters . But margins of victory aren't terribly important when it comes to road league games in November. Besides, the Big 12 championship is essentially all the Sooners have left to play for -- and the rankings don't matter for that.

Iowa State: The Cyclones once again showed glimpses of promise. But they're not ready to beat a team as talented as the Sooners just yet. Still, Iowa State looked respectable for a program that had dropped its previous 11 games to coach Bob Stoops by an average score of 41-9.

FLOWERS BLOOMS

With Joe Mixon (suspension) and Samaje Perine (injury) out of action Thursday, Dimitri Flowers stepped in to give Oklahoma a running game with 115 yards on 22 carries. Freshman Abdul Adams added 54 yards. "I told him in the locker room in front of the whole team, I don't believe I've ever seen a guy do all of that, what he did, so well in a game," Stoops said of Flowers. "And he had two days of practice to do it."

THE NUMBERS

Mayfield, who was 25 of 34 passing, has 19 TDs and just 2 picks last four games. ...Westbrook now has four TD grabs of at least 65 yards this season. ... Oklahoma has allowed just 27 points in its last two games. Granted the Sooners played Kansas and Iowa State, but they allowed 59 against Texas Tech before that. ... Joel Lanning is quickly becoming Iowa State's backup quarterback. Lanning threw just one pass, an incompletion, though his 41-yard TD run in the second quarter gave the Cyclones a 17-14 lead. That gave Iowa State fans hope that an upset was possible, but Mayfield proved to be too tough to stop.

UP NEXT

Oklahoma hosts the 13th-ranked Bears in a matchup with serious Big 12 title implications. The Sooners won their first 20 matchups against the Bears, but are 2/3 the past five years.

Iowa State travels to face Kansas in the least appealing matchups in the Big 12 this year. The Jayhawks are 1-7 and have lost their last three games by an average of 40 points.