Oklahoma's designs on the College Football Playoff may have just blown away in a cyclone.

​One day after Iowa State announced that starting quarterback Jacob Park was taking leave from the team for undisclosed medical reasons, third-stringer Kyle Kempt helped the visitors overcome two 14-point deficits and score a massive upset over the third-ranked Sooners at Owen Field Saturday, 38-31.

Kempt entered the game without a single pass attempt on the season, but finished 18-24 for 343 yards and three 3 touchdowns. Most notably, he decisively outdueled Sooners gunslinger and Heisman Trophy contender Baker Mayfield.

"I don't think he's a third-string quarterback anymore," Iowa State head coach Matt Campbell said after the game.

Kempt came up huge all game long, but saved the best for last, answering Oklahoma's tying touchdown with a game-winning 25-yard strike to Allen Lazard with 2:19 left.

Coming off a 10-point loss to Texas, the Cyclones came into the Palace on the Prairie as 31-point underdogs.

They left with the year's biggest upset in Power 5 football.