Trevone Boykin led three straight scoring drives after starter Casey Pachall left with an injury game, and No. 24 TCU pulled away from Southeastern Louisiana 38-17 on Saturday.
Pachall appeared to injure his left arm or wrist at the end of a running play late in the second quarter. Boykin ran 16 yards on the next play, and Jaden Oberkrom ended the first half with a 46-yard field goal that put the Horned Frogs (1-1) ahead 17-14.
Boykin completed a 29-yard pass to Brandon Carter on the first play of the second half, and Carter finished that drive with a 5-yard scoring run. Then Boykin threw 27 yards to Josh Doctson for a 31-14 lead.
Bryan Bennett had 132 yards passing and another 132 rushing for the Lions (1-1), who had never scored more than 10 points in five games against BCS teams since bringing back football in 2003 at the FBS level.
Boykin took over at quarterback last year when Pachall was arrested on suspicion of drunken driving after starting the first four games. Pachall missed the rest of the season and entered a substance-abuse program before returning in the spring.
The quarterbacks split time in the opener against LSU, and both were on the field for the first play. Pachall took just about every snap against Southeastern Louisiana before getting injured, and Boykin had the first three catches of his career.
Boykin's first play under center was a handoff to Waymon James for the game's first score, a 1-yard plunge.
Pachall led a pair of scoring drives and finished 8 of 14 for 100 yards. Boykin was 9 of 13 for 133 yards and two touchdowns and added 35 yards rushing before he was replaced by third-stringer Tyler Matthews late in the game.
Bennett, a transfer from Oregon, had a 45-yard run to set up the Lions' first touchdown, and threw a 65-yard scoring pass to Jeff Smiley to pull even at 14 late in the second quarter.
The 14-14 tie late in the first half was a bit of a shocker considering Southeastern Louisiana had been outscored 272-26 in five previous games against BCS teams going back to 2006.
Smiley ran untouched down the sideline on the same play that TCU failed to defend earlier, when Bennett overthrew Xavier Roberson on what would have been an easy 25-yard score.
Bennett, who also lost a fumble, threw the first of two interceptions on the next play with his team in field goal range.
Facing the Big 12's best defense from a year ago, the Lions had 207 yards rushing a week after they picked up 309, their most since the program's return.
Defensive end Devonte Fields played the second half for TCU after missing the first game and a half as part of a two-game suspension for an unspecified violation of team or university policy during the offseason. Fields had one tackle.
Coach Gary Patterson had said he wanted to get Fields some playing time before the Big 12 opener at Texas Tech on Thursday night. Fields still must serve another half-game suspension.