SMU's defense played as well as it could, but couldn't get any help from its offense.
After taking a halftime lead thanks to a defense that kept TCU guessing, the Horned Frogs took advantage of turnovers and short fields en route to a 48-17 victory against the rival Mustangs on Saturday.
TCU forced five turnovers, sacked Garret Gilbert seven times and used a 31-point fourth quarter to reclaim the Iron Skillet. TCU is 11-2 under coach Gary Patterson in the annual rivalry game.
SMU had a 10-7 halftime lead before Gilbert threw three of his four interceptions after halftime.
"Our defense played a heck of a game today," said Gilbert, who completed 23 of 44 passes for 276 yards and two touchdowns. "Offensively that's completely on us. We didn't keep them off the field by sustaining drives in the second half. Felt great about the first half, played well, thought we had some stuff to build on."
The Mustangs (1-3) had plenty to build on, but TCU quarterback Trevone Boykin made sure to quash that early.
Boykin completed 15 of 26 passes for 228 yards and two touchdowns.
He overcame a 7 of 16 first-half performance by completing seven of his first nine passes in the second half, tossing touchdown passes of 20 and 56 yards to help the Horned Frogs (2-2) overcome the deficit.
TCU scored on five straight offensive possessions during a run in the second half.
The Frogs had seven sacks, their most since eight in 2009 at Virginia, even without star defensive lineman Devonte Fields, who was out with an unspecified injury. Fields was the Big 12 defensive player of the year as a freshman last season.
TCU's defense stepped up in the second half, forcing six straight incompletions from former Texas starter Gilbert and picking up the pass rush. After TCU tied the game at 10 on a 35-yard field goal by Jaden Oberkrom, Gilbert was intercepted by Sam Carter and returned 25 yards to the SMU 32.
After driving inside the 10 following the interception, the snap went through the legs of Boykin to set up a third-and-18 from the 20, but the sophomore quarterback found Ty Slanina in the left corner of the end zone to put the Frogs up for good.
"You have to go make plays at the wide receiver position, and finally we did that a little bit," Patterson said.
Boykin led five straight scoring drives in the second half, which included a 6-yard touchdown run by B.J. Catalon with 10:33 left in the fourth quarter to give TCU 31-10 lead.
After SMU cut the lead to 35-17 with 3 minutes left in the game, LaDarius Brown returned an onside kick 45 yards for a touchdown, and Carter returned his second interception of the game 66 yards for another score.
It was a lopsided score even though TCU lost two fumbles and was only 2-of-12 on third downs.
"It wasn't pretty early," Patterson said.
The Frogs, playing for the first time in 16 days since losing their Big 12 opener at Texas Tech, went four possessions without a first down in the second quarter, which included a missed 42-yard field goal after an SMU fumble in its own territory.
They then stalled at their own 10 late in the first half. Then Ethan Perry's punt was deflected by Jackson Mitchell close to the end zone. The ball sailed to the 11 and was picked up by Ajee Montes, who returned it to the 1.
Fortunately for the Frogs, SMU's offense fared no better in the opening half. After Prescott Line was dropped for a loss of 1, Gilbert fumbled a low snap and although the Mustangs recovered, SMU had to settle for a 34-yard field goal by Chase Hover with 58 seconds left in the half.
"We had a blocked punt that we didn't score and only got a field goal out of it," SMU coach June Jones said. "You got to score touchdowns, but we gave them an opportunity to feel like they had some success."
The Mustangs opened the scoring with a 1-yard touchdown pass from Gilbert to Jeremy Johnson with 4:41 left in the first quarter. Johnson led SMU with 11 catches for 159 yards.
Waymon James, who led TCU with 54 yards rushing on 11 carries, scored from 2 yards out 9 seconds into the second quarter to make it 7-7.