STILLWATER, Okla. -- Big plays and red-zone failures continued to dog TCU.
Oklahoma State spotted TCU a 14-point lead Saturday before storming back in front of 57,183 at Boone Pickens Stadium and won going away 36-14.
The Horned Frogs (5-3, 2-3 in the Big 12) have lost more than two games in a season for the first time since 2007. That year TCU finished 8-5 with a bowl win.
With four games remaining, beginning next week at West Virginia, TCU has a shot to keep its streak of seven consecutive bowl berths alive with one more win.
But it's not going to be easy, especially with the injury count continuing to rise.
Quarterback Trevone Boykin, who replaced Casey Pachall four weeks ago, left the game with a leg injury late in the fourth quarter. He was injured after being hit while throwing an interception with the game out of reach and under three minutes to play.
The Cowboys (5-2, 3-1) scored their final touchdown on the next play to put an exclamation point on the overwhelming turn of events.
TCU led 14-0 with 3:22 left in the first quarter after Elisha Olabode returned an interception 11 yards for a score and Boykin connected with LaDarius Brown for an 18-yard scoring pass.
From that point, however, Oklahoma State's defense clamped down and the Cowboys' offense loosened up.
Quarterback Wes Lunt, making his first start since an injury Sept. 15, threw for 324 yards and a touchdown. He gained momentum in the second half and helped turn a 14-9 halftime deficit into a 16-14 lead midway through the third quarter.
Lunt completed all three pass attempts for 40 yards of a 69-yard drive that put the Cowboys ahead for the first time on Jeremy Smith's 1-yard run on fourth-and-goal.
"We have to get more bullets," TCU coach Gary Patterson said. "We allowed [Lunt] to get some confidence. You've got to give him credit. The guy hasn't played in five weeks."
Boykin led the Frogs into scoring position on their ensuing possession, getting to the OSU 11 before B.J. Catalon was dropped for a 3-yard loss on third-and-2.
Jaden Oberkrom, who was awarded a national kicking award last week after setting a TCU and Big 12 record with six field goals against Texas Tech, missed wide right from 31 yards, preserving OSU's lead. Oberkrom also missed a 52-yard attempt just before halftime.
Lunt came right back to burn TCU deep with a 46-yard pass to Blake Jackson on the Cowboys' next offensive play. OSU drove 80 yards on five plays and took a 23-14 lead on Lunt's 20-yard scoring pass to Charlie Moore.
"We let our foot off the throttle and they made plays and we didn't," said defensive end Jon Koontz, who played in place of the injured Stansly Maponga for the second consecutive game. "It was the same stuff, they were just executing and we weren't when it came down to it. They definitely have a fast-paced offense, but I don't think that was a factor. We're conditioned for that. We just weren't making the plays we needed to."
Oklahoma State kicker and Mansfield Summit High School ex Quinn Sharp made a career-high five field goals, including three in the first half to pull the Cowboys back into it at 14-9.
The Frogs still only trailed 26-14 and were driving when Oklahoma State recovered a fumble on a bizarre play. The ball was knocked loose as Boykin attempted a pass. It landed about 10 yards downfield. TCU receiver Skye Dawson made a play for the ball as if he were concerned it was a fumble, but as he approached the ball he disregarded it and walked away. At that point, OSU's Nigel Nicholas picked it up at the urging of his teammates on the sideline and returned it 22 yards to the OSU 43.
Sharp's fifth field goal capped a time-consuming OSU drive and gave the Cowboys a 29-14 lead with 2:32 remaining.
"We did a good job early of holding them to field goals, but when you get your chances on offense you've got to make plays and we didn't do that," Patterson said. "We only scored one touchdown. I'd say that's not good enough to win in the Big 12. It's two weeks in a row in the fourth quarter when [opponents] have turned it up and we just haven't had an answer.
"I don't know if it's because of the injuries and we're just worn down. I think you have to give them a little bit of credit -- [defensive coordinator] Bill Young and his defense didn't allow the big play."