Irwin was replaced first by Tyrus Thompson and then by Austin Woods when Thompson's helmet popped loose on a play.
Irwin was able to get back on the field by the start of the next drive.
STILLS GOES OVER 2,000
Kenny Stills became the sixth Sooners receiver with more than 2,000 career receiving yards.
Stills had three catches for 37 yards.
He passed Antwone Savage for fifth on the Sooners' career list with 2,016. Stills is three behind Savage for seventh on the receptions list.
WHALEY STAYS SILENT
While Damien Williams led the way for the Sooners resurgent running game, Dominique Whaley, who started OU's first three games, was virtually invisible.
Whaley didn't enter the field until the third quarter and finished with six carries for 51 yards.
Fullback Aaron Ripkowski got his first start of the year as OU began with a pair of fullbacks on the field.
ASH, JEFFCOAT INJURED
Not only did Texas lose, the Longhorns lost a pair of their top players.
Quarterback David Ash left the game in the fourth quarter after being hit by Sooners defensive end Chuka Ndulue.
Ash was clutching his left wrist after the hit and shortly after the injury he walked to the locker room.
Longhorns defensive end Jackson Jeffcoat also left the game with a left-shoulder injury.
Texas said both players would be reevaluated in Austin.
TEXAS' SOONER ROOTS
A pair of former Oklahoma high school standouts wore the Longhorns' white Saturday.
Former Tulsa Central standout Demarco Cobbs had nine tackles while former Millwood standout Josh Turner had four tackles.
Jaydan Bird's tackle of Joe Bergeron in end zone in the second quarter was the Sooners first safety since Nov. 20, 2010 when a forced fumble went out of the back of the end zone vs. Baylor. The safety was set up by Justin Brown's downing of Tress Way's punt inside the 1. ... Oklahoma is 29-0 under Stoops with a 100-yard receiver and a 100-yard rusher. ... OU's 36 first-half points were the most against Texas since 2003. ... Brennan Clay's 42-yard kickoff return in the second was a career-long.