Harrell drove the Red Raiders (9-0, 5-0) to the touchdown in six plays, slinging the long pass to Crabtree, who broke the tackle of Curtis Brown near the sideline, kept his balance and scooted the last five yards for a score. If he had been tackled inbounds, the clock likely would have run out.
Thousands of Texas Tech fans poured onto the field and had to be sent off while the play was under review. Once the fans were chased off the field and Tech kicked the extra point, the Red Raiders were penalized and forced to kick off from their own 7.
When Texas couldn't pull of a miracle kickoff return, the fans ran back on the field to celebrate the biggest win in Texas Tech history.
Texas had just appeared to pull off a stunning rally behind Colt McCoy, who threw second-half touchdown passes of 37 and 91 yards to Malcolm Williams and led Texas on a grinding drive to its final touchdown after Texas Tech's Danny Carona kicked a field goal for a six-point lead.
McGee's burst stunned the home crowd until a big kickoff return by Jamar Wall gave the Red Raiders the ball at their own 38 and time to move. Harrell hit on four straight passes, to get the ball in Texas territory when the Red Raiders were just trying to set up for a winning field goal.
He also got break when Texas freshman safety Blake Gideon dropped what would have been a game-ending interception on a tipped ball.
Facing third down, Harrell fired the risky pass to the All-American Crabtree, who snagged it just inside the five and shrugged off Brown's tackle.
Harrell, who may have jumped ahead of McCoy in the Heisman Trophy race, just as the Red Raiders will likely jump ahead of Texas in the rankings, finished with 474 yards passing and two touchdowns on 36-of-53 passing.
Texas Tech also took command of the race in the Big 12 South with the win.
McCoy finished with 294 yards and two touchdowns and had an interception returned for a touchdown in the third quarter.