NCAAF College Football News, Photos, Stats, Scores, Schedule & Videos...

The UCF Knights' defense, which the team is confident in, crumbled in back-to-back second halves, crushing hopes of upsetting ranked teams.

UCF allowed 21-plus unanswered points in the second half before scoring its first touchdown late. The then-No. 20 Houston Cougars scored 27 unanswered points last Saturday and the No. 18 Oklahoma State Cowboys scored 21 straight points.

Houston quarterback Conner Weigman tallied a career-high three rushing touchdowns in the third and fourth quarters. Oklahoma State's defense got a scoop-and-score, and quarterback Drew Mestemaker threw his second passing touchdown in the fourth quarter.

Here are three defensive takeaways from the Knights' collapse on Saturday.

Pass Rush Couldn’t Pressure Mestemaker

UCF's pass rush finished with one sack against Mestemaker, something defensive coordinator Alex Grinch wanted to improve. It's the second straight week the team has finished with one sack.

The Cowboys' offensive line allowed three sacks entering Saturday's game. They created a clean pocket for their star quarterback, who threw for 304 yards and two touchdowns.

A lack of pressure forces the UCF secondary to play their assignments to perfection, which becomes difficult over an entire game.

Knights Didn’t Create Multiple Turnovers

Grinch and the defense have emphasized creating turnovers as their identity. Defensive back Antione Jackson forced an early fumble on Cowboys running back Caleb Hawkins and EDGE Isaiah Nixon recovered.

That was their only turnover of the game.

UCF forced a fumble last week against Houston in the red zone. Defensive back Jayden Williams headbutted the ball out of tight end Patrick Overmyer's grasp.

Grinch believes turnovers are a significant influence on the game's outcome, saying the team that generates the most takeaways often wins.

Mestemaker Completed Multiple 20-Plus Yard Passes

UCF's defense held Oklahoma State to a field goal, but allowed Mestemaker to complete a 48-yard pass to wide receiver Miles Coleman in the third quarter.

The Mestemaker-Coleman connection got the Cowboys out of their territory and placed them at UCF's 34-yard line. It's become a trend for the defense to allow these backbreaking plays.

Oklahoma State's star quarterback completed a 27-yard pass in the fourth quarter after running back Landen Chambers failed to convert a fourth-and-1. Mestemaker threw his second passing touchdown to wide receiver Wyatt Young.

Grinch must fix these woes and adjust to his opponent's halftime adjustments. A top-three pass defense last season has regressed to the 12th-best in the conference, allowing 236.8 yards per game.

More at NCAAF College Football News, Photos, Stats, Scores, Schedule & Videos