Breece Hall scored on a 3-yard touchdown run with 1:25 to play to lift No. 15 Iowa State to a 23-20 come-from-behind victory over No. 20 Texas on Friday in a key Big 12 Conference dustup in Austin, Texas.

Hall, the nation's leading rusher entering the contest with an average of 148 yards per game, was held to 91 yards on 20 carries, the first time this season he had been held to less than 100 yards.

Texas had a final chance to get in position to attempt a tying field goal, moving to the Iowa State 36 before quarterback Sam Ehlinger took a sack with three seconds left. Cameron Dicker's 58-yard attempt on the game's final play sailed wide left, granting the Cyclones the win.

It's the first time the Cyclones have defeated Oklahoma and Texas in the same season and all but guaranteed Iowa State a spot in the Big 12 Championship game on Dec. 19 in Arlington, Texas. Iowa State has not won a conference title since 1912 and has never played in a conference championship game.

Brock Purdy threw for 312 yards and a score for the Cyclones (7-2, 7-1 Big 12) with tight end Charlie Kolar hauling in six catches for 131 yards.

Ehlinger passed for 298 yards and a score and ran for 65 yards and another TD in his final home game. Brennan Eagles caught five passes for 142 yards to lead the Longhorns (5-3, 4-3).

Texas scored on all three of its first quarter possessions, as field goals from Dicker -- from 21 and 42 yards, respectively -- were sandwiched around a 17-yard TD run by Ehlinger. Iowa State countered with a 35-yard touchdown pass from Purdy to Sean Shaw.

Connor Assalley's 26-yard field goal midway through the second quarter brought the Cyclones to within 13-10 but his chance to tie the game via a 41-yard attempt on the half's final snap was short and right.

The Longhorns added to their lead on their first possession of the third quarter via a 7-yard scoring pass from Ehlinger to Jared Wiley.

Assalley booted a 29-yard field goal with 2:54 to play in the third quarter and another, from 38 yards away, on the second snap of the fourth quarter to cut Texas' lead to 20-16.