AMES, Iowa — Seth Doege tossed three touchdown passes and Texas Tech held off host Iowa State 24-13 on Saturday night in the Big 12 opener for both teams.

Doege threw for 331 yards to lead the unbeaten Red Raiders (4-0, 1-0), who held Iowa State to just 189 yards of offense.

Doege’s 19-yard TD pass to Eric Ward put Tech up 21-13 with 10:36 left, and Ryan Bustin added a 39-yard field goal with 2:20 to go.

James White had 57 yards rushing for the Cyclones (3-1, 0-1). Iowa State’s Steele Jantz had one of the worst nights of his career, throwing for just 73 yards on 10 of 20 passing to go with three interceptions and a fumble.

The pick that Tech turned into the go-ahead touchdown wasn’t his fault.

But the fumble that sealed Iowa State’s fate was all on him.

Ernst Brun Jr. caught the ball near midfield, but the ball popped out after he was drilled by D.J. Johnson. Cornelius Douglas brought the ball back to Iowa State’s 9-yard line, and after a holding penalty, Doege found Ward for the score.

The Cyclones then got into Red Raiders territory with just under seven minutes left when the ball slipped out of Jantz’s hands on a scramble.

Texas Tech recovered near midfield and ran down the clock before Bustin’s decisive field goal.

Jantz also gained just 14 yards on 19 rushes, and his final interception came in the Tech end zone with 57 seconds left.

Jantz threw for just 3 measly yards on seven passes in the first half. But he picked up 21 yards on a crucial third-and-20 and found Brun in the back corner of the end zone to put the Cyclones ahead 13-7.

It all went downhill from there for the Cyclones.

Tech answered right back on Doege’s 4-yard TD pass to Darrin Moore that made it 14-13 Red Raiders with 1:01 left in the third quarter.

The Cyclones forced Texas Tech into a 41-yard field goal try by Bustin that was wide right early in the fourth quarter, but a relatively solid night defensively for Iowa State went unrewarded.

The Cyclones held the Red Raiders to just 63 yards rushing and a season-low 24 points.

Texas Tech rolled over its first three opponents — Northwestern State, Texas State and New Mexico — with such ease that the Red Raiders entered play ranked first in the nation in total defense and second in total offense.

Tech, which lost to Iowa State 41-7 in 2011, realized this wouldn’t be another easy romp.

The Red Raiders punted as many times in the first seven minutes, twice, as it had all season. The Cyclones also kept getting in Doege’s face, and on a key third down Doege threw it right to Klein, who took it back 87 yards for the touchdown.

But Klein missed a tackle on Texas Tech’s Jakeem Grant on an 11-yard TD reception that tied the game at 7 with 1:32 left in the first half.

Texas Tech’s defense would prove worthy of its ranking in the national standings, holding Iowa State to 3.3 yards per play and making it pay for Jantz’s mistakes.