Rex Burkhead scored the go-ahead touchdown in overtime, and the Cornhuskers thwarted a 2-point conversion minutes later as No. 10 Nebraska defeated Iowa State, 31-30, on Saturday.

After Burkhead scooted around left end for a 19-yard touchdown, Cyclones quarterback Austin Arnaud threw a 9-yard scoring pass to Jake Williams. Instead of going for the tie, Iowa State (5-5, 3-3 Big 12) tried for the win, but Nebraska (8-1, 4-1 Big 12) defensive back Eric Hagg picked off a pass intended for Collin Franklin.

Nebraska won despite starting quarterback Taylor Martinez sitting out with an injured knee. Cody Green started in his place and completed 7-of-12 passes for 79 yards.

A 57-yard field goal by Grant Mahoney made it 10-7 Iowa State at half, but Nebraska scored all 17 points in the third quarter to forge a 24-10 edge. The Cornhuskers had two interceptions in the period, including one by defensive back Austin Cassidy, who returned it 30 yards for a touchdown. 

But the Cyclones scored early in the fourth on a 1-yard run by Arnaud, and they recovered a Husker fumble on the ensuing kickoff. Arnaud cashed in the turnover with a 14-yard touchdown pass to Alex Robinson that tied the game 24-24 with 11 minutes left.

Arnaud finished 21of 32 for 203 yards with three touchdowns and two interceptions.

Roy Helu Jr., who rushed for 307 yards against Missouri last week, ran for 99 yards on 22 carries and opened the scoring with a 6-yard touchdown run.