The timing of his return was fortuitous for the Cowboys, who lost backup quarterback J.W. Walsh to a season-ending knee injury after a win last Saturday over Iowa State. Lunt beat out Walsh and Clint Chelf in spring practice for the starting job.
''He got better as it went on,'' Oklahoma State coach Mike Gundy said of Lunt. ''I think his confidence is good. He's very level-headed. He's a very cerebral young man, and I don't think he doubted himself. I just think it's human nature, and he had to grow into it. He got hit a few times and realized it was going to be OK.''
Lunt completed 18 of 33 passes for the Cowboys (5-2, 3-1 Big 12) in their first meeting with TCU (5-3, 2-3) since 1993. He guided Oklahoma State on third-quarter touchdown drives of 64 and 80 yards to erase TCU's 14-9 halftime lead.
Gundy won't let first-year players speak with reporters, so Lunt wasn't available for comment. But Lunt's teammates were more than willing to heap praise on the true freshman, who went the distance for just the second time in his brief career.
''He did more than what we expected,'' running back Joseph Randle said. ''He did a great job out there.''
Added wide receiver Josh Stewart: ''Wes is always quiet. You can never tell his emotion. Today, once we got going, he was always smiling. Once you see him with a smile, you know something is going on right.''
Lunt had plenty of support in his return. Randle was a workhorse, rushing for 126 yards and a touchdown on 32 carries, while Stewart caught six passes for 120 yards. The defense had three takeaways as the Cowboys held their third straight conference opponent under 20 points - the first time they've done that since starting Big 12 play in 1996.
TCU is 1-3 since suspending starting quarterback Casey Pachall after he was arrested on suspicion of drunk driving. His replacement, Trevone Boykin, was 21 of 40 for 185 yards as the Horned Frogs' streak of scoring at least 20 points ended at 33 games, which had been the nation's longest such run. Oklahoma State now has the current longest streak at 33 games.
Texas Christian, which lost in triple overtime to Texas Tech a week earlier, has dropped consecutive games for the first time since falling to Texas and Air Force in 2007. The Horned Frogs had won 14 straight conference road games, the longest streak in the nation. That streak dated back to TCU's time in the Mountain West Conference.
The Horned Frogs went three-and-out five times in the second half.
''It was obvious in the third quarter, and for the second week in a row, that when they turned up the gas, we couldn't finish,'' Texas Christian coach Gary Patterson said. ''I have to give Oklahoma State a lot of the credit. They did a great job. We did a good job of holding them early to field goals, but you have to make plays when you get your chances on offense. We didn't do that. We can't turn the ball over.''
Boykin limped off the field after being hit while throwing an interception with 1:26 remaining. Matt Brown finished the game at quarterback for the Horned Frogs. Asked if Boykin was OK, Patterson said, ''I have no idea.''
The Cowboys - who entered the game leading the FBS in total offense - didn't record a first down until the 3:03 mark of the first quarter and had three first-half drives stall inside the TCU 20. Lunt's first pass was thrown slightly behind Stewart, and the football bounced off the receiver's hands to TCU safety Elisha Olabode, who returned it 11 yards for a touchdown.
A 46-yard run by TCU's B.J. Catalon - on which he broke two tackles - set up an 18-yard touchdown pass from Boykin to LaDarius Brown, putting the Horned Frogs up 14-0 with 3:22 left in the first quarter.
Sharp hit field goals of 22, 24 and 30 yards before halftime for the Cowboys. The last one came after a holding call wiped out a 30-yard touchdown pass on a trick play, as Lunt lateraled to Randle, who hit Blake Jackson in the end zone.
The Cowboys took their first lead, 16-14, midway through the third quarter, with Jeremy Smith plunging in from the 1-yard line on fourth down. TCU almost answered, but Jaden Oberkrom banged a 33-yard field-goal attempt off the right upright. He earlier had missed a 52-yard attempt.
''We had our chances and we were in the ball game, but we couldn't do much with it in the second half, except for that one drive,'' Patterson said. ''We missed two field goals while they took care of their opportunities. We only scored one (offensive) touchdown, and that's not good enough to win in the Big 12.''
Lunt capped the next series with a 20-yard TD pass to Charlie Moore. Sharp's 32-yard field goal after the next drive extended Oklahoma State's lead to 26-14 early in the fourth quarter.
Defensive tackle Nigel Nicholas sealed the win for Oklahoma State on a bizarre play. Nicholas knocked the ball loose from Boykin just as the quarterback's arm was starting forward. Players on the field stopped, thinking it was an incomplete pass, but no whistle blew, and Nicholas ran to the ball, picked it up and returned it before being tackled.
Sharp's 27-yard field goal with 2:32 left allowed him to match the single-game school record, set by Larry Roach against Missouri in 1982.