On a raw and rainy day, Oklahoma shut down Iowa State quarterback Seneca Wallace and avoided a letdown after the Sooners' emotional, 35-24 win over Texas last week.
Oklahoma improved to 7-0 for the year and to 3-0 in the Big 12 South. Simms' touchdown recovery came at the end of Iowa State's first possession and the Sooners did not ease up.
"Our game plan every week is try and dominate up front," Oklahoma defensive tackle Kory Klein said. "We wanted to make them one-dimensional. We were fortunate to stop the run and make them pass to beat us."
Iowa State (6-2, 3-1 Big 12 North) had been off to its best start since 1938. The Cyclones were outgained in the first half, 206 yards to four.
Wallace likely saw his Heisman Trophy hopes washed away following a nightmare performance. He completed one of 12 passes for zero yards in the first two periods and finished four of 22 for 43 yards and three interceptions.
"It was an incredible defensive game against a tremendous player," Oklahoma Coach Bob Stoops said. "We still believe Seneca Wallace is a guy who deserves all the Heisman attention he has gotten."
As the rain intensified, the Sooners continued to pour it on with Quentin Griffin and Kejuan Jones each rushing for a pair of touchdowns in the opening 30 minutes.
"It was really tough to bounce back and get into a rhythm after the way the first half went," Wallace said. "Our game was just to have offense, period."
Griffin surpassed the century mark for the ninth time in his career, rushing for 111 yards on 23 carries. Jones added 86 yards on 25 attempts.
"Quentin is just making people miss," Oklahoma offensive tackle Jamaal Brown said. "Once he gets off the line of scrimmage, he makes people miss and gets 10 or 15 yards that he shouldn't get."
Oklahoma continued its dominance of Iowa State in one of the nation's most lopsided rivalries, increasing its lead in the all-time series to 64-5-2.
The Cyclones dropped to 0-49-2 against top-five opponents. Iowa State visits Texas next week, then has road games at Kansas State and Colorado in November.
"Their defense was about the best I've coached against and I've around for a long time," Iowa State Coach Dan McCarney said. "I don't believe I've ever played against a defense as good as that one. They dominated our offense from beginning to end."
The lone highlight for Iowa State came in the first half came when Mark Clayton recovered a fumbled punt at the Oklahoma one-yard line with just under four minutes left. But the Sooners kept Iowa State out of the end zone and took over on downs.
Iowa State, got its only points on Adam Benike's 29-yard field goal in the third quarter.
"From the way we played this year, I didn't think we'd get beat like this," Iowa State wide receiver Lane Danielson said. "They were very tough."
Oklahoma dominated every aspect of the contest. The Sooners picked up 25 first downs to just five for the Cyclones and held a 367-60 edge in total yardage. Iowa State was none for 12 on third-down conversions while Oklahoma was 10 of 21.
Oklahoma's Nate Hybl tossed a 22-yard touchdown pass to Brandon Jones later in the third period before Renaldo Works' 11-yard scoring run capped an eight-minute drive for the Sooners in the fourth quarter.
Hybl made no spectacular plays but completed 14 of 24 passes for 168 yards in an efficient performance. Griffin scored on runs of 15 and four yards to give the Sooners a 21-0 lead early in the second quarter before interceptions set up Oklahoma's final two scores of the first half.
Brandon Everage led Oklahoma's dominant defense with two interceptions, a sack and a forced fumble. His first interception set up a 13-play, 72-yard drive that Jones capped with a one-yard plunge.