AMES, Iowa (AP) - Backup running back Jeff Woody scored on a 4-yard run in the second overtime and Iowa State stunned second-ranked Oklahoma State 37-31 on Friday night, derailing the Cowboys' national title hopes.
The Cyclones (6-4, 3-4 Big 12) overcame a 17-point deficit to beat the Cowboys (10-1, 7-1 Big 12), who were just a win away from a showdown with rival Oklahoma for a likely spot in the BCS title game.
Oklahoma State quarterback Brandon Weeden's first pass in the second overtime was intercepted by Leonard Johnson. Woody ran for 6 and 15 yards, then bullied his way into the end zone to give the Cyclones their first victory over a top-five opponent in school history.
Weeden threw for 476 yards, but he had three interceptions as the Cowboys turned it over five times.
Oklahoma State was a 27-point favorite against the upstart Cyclones, who lost their first four Big 12 games. But the Cowboys let Iowa State hang around just long enough to beat them - and throw the national title picture into chaos.
Iowa State freshman quarterback Jared Barnett found James White for a 25-yard touchdown on the first play of extra time, but Weeden answered with a 6-yard TD pass to Josh Cooper.
Johnson's interception set up a thrilling finish for the Cyclones and coach Paul Rhoads, the defensive coordinator at Pittsburgh when it upset No. 2 West Virginia 13-9 in 2007.
Barnett finished with 376 yards passing and three TDs for Iowa State.
Oklahoma State stretched its lead to 24-7 less than 3 minutes into the second half and looked set to break it open as it usually does. Tracy Moore caught Weeden's pass in traffic and stumbled 30 yards for the touchdown.
That could have been it for Iowa State - but the Cyclones were far from finished.
Iowa State answered with a 32-yard TD run from White and recovered an onside kick with ease. Barnett fumbled it back to Oklahoma State, but the Cowboys fumbled it right back and Zach Guyer's 24-yard field goal made it 24-17 with 4:04 left in the third quarter.
Oklahoma State came in averaging 51.7 points a game, but it couldn't string together the drives that made Weeden a serious Heisman Trophy contender.
Iowa State tied the game at 24-all with 5:30 left in regulation as Barnett found a sliding Albert Gary in the end zone for a 7-yard TD catch. Oklahoma State's Alex Elkins intercepted Barnett's pass with 3:17 left, but Sharp pushed a 37-yard field goal right with 1:17 to go to force overtime.
It was just the third missed field goal in 20 tries for Sharp.
Iowa State knew it would need a lot of breaks to pull off the upset.
The Cyclones caught a few early, recovering Randle's fumble and intercepting Weeden's pass in the first quarter. But they didn't turn either into points, and the Cowboys' defense made them pay for it.
Linebacker Shaun Lewis jumped Barnett's pass and took it back 70 yards for a touchdown, giving Oklahoma State a 7-0 lead late in the first quarter.
Iowa State pulled to 10-7 on Barnett's 16-yard TD pass to Darius Reynolds. But Blackmon stopped short and went high for Weeden's pass over a pair of defenders on a 27-yard touchdown reception, giving Oklahoma State a 17-7 lead with 5:26 left before halftime.
The Cowboys were playing a day after women's basketball coach Kurt Budke and three others were killed in a plane crash.
Iowa State held a moment of silence before the game to honor Budke, assistant Miranda Serna and two others who were killed Thursday when their single-engine plane crashed during a recruiting trip in Arkansas.