LINCOLN, Neb. — Steven Sheffield passed for a touchdown and ran for two in his first road start, and Texas Tech jumped out fast to upset No. 15 Nebraska 31-10 Saturday.

Sheffield, who passed for 490 yards passing and seven touchdowns in his debut as the starter against Kansas State last week, was nearly perfect early, completing 14 of his first 16 passes against the Cornhuskers. Playing for the injured Taylor Potts, Sheffield went 9-for-16 in the second half and finished with 234 yards.

Texas Tech (5-2, 2-1) won for the first time in four road games since last October. Nebraska (4-2, 1-1) held the Raiders to 259 yards — 263 under their average.

But Nebraska's offense for the second straight week did next to nothing until the fourth quarter. By then it was too late.

Tech's often-overshadowed defense, led by end Brandon Sharpe, allowed just one field goal until the middle of the fourth quarter.

Sharpe had four sacks and batted down a pass, and strong safety Franklin Mitchem had seven tackles and an interception.

Sheffield picked up where he left off last week against K-State. He completed all six of his passes while leading the Red Raiders on an 80-yard touchdown drive to start the game, finishing with a 16-yarder to Baron Batch.

Sheffield couldn't get anything going on his next series, but Tech's defense provided a big lift. Nebraska's Niles Paul fumbled after taking a lateral from Zac Lee, and Daniel Howard picked up the ball and ran it back 82 yards for a 14-0 lead.

Rajon Henley and Sharpe sacked Lee on back-to-back plays before Sheffield ran in from a yard to wrap up a 12-play, 65-yard drive that put Tech up by three TDs.

Tech led 24-3 at half after the teams traded field goals.

The Raiders generated 47 yards in the second half, but their defense never let the Huskers get closer than two touchdowns.

Nebraska backup Cody Green, who played one series in the third quarter, replaced Lee in the middle of the fourth and found Khiry Cooper for a 13-yard pass that was Nebraska's only touchdown.

Green drove the Huskers inside the Tech 15 late in the fourth quarter before getting intercepted by Mitchem.

Lee had the Huskers inside the Tech 10 early in the fourth before they self-destructed. Offensive lineman Ricky Henry got a personal foul for pushing the pile after the whistle, and center Jacob Hickman was called for a false start. The series ended with Lee throwing out the back of the end zone, prompting boos from frustrated fans.

In 12 quarters against BCS opponents, Nebraska has failed to score a touchdown in 10 of them.

Lee was 16 of 22 for 128 yards and Green 7 of 16 for 87.