ORLANDO, Fla. -- So many times No. 21 UCF has had to rely on its offense to be the savior in its biggest moments this season.
This time, it was the Knights' defense that saved the day and possibly their hopes of earning the school's first trip to the BCS.
With team leader and quarterback Blake Bortles struggling, UCF's defense kept pressure on one of the nation's top scoring attacks and hung on for 19-14 win over Houston Saturday night.
Freshman William Stanback scored two touchdowns and the Knights survived three turnovers to hold off a late Houston threat and keep first place in the American Athletic Conference.
"I thought defensively, to hold that team to 14 points, and (to have) a great play at the end of the game to save the win, that was a big-time team win," Knights coach George O'Leary said.
Storm Johnson added 127 yards rushing for UCF (7-1, 4-0), which now has the inside track to the league's automatic BCS bid, with victories against the Cougars and Louisville.
The Cougars drove to the UCF 10 in the final minute, but came up empty on back-to-back passes from John O'Korn into the end zone. The first went off star receiver Deontay Greenberry's finger tips and the second sailed high.
O'Korn had a touchdown pass and two interceptions for the Cougars (7-2, 4-1).
The Knights had three giveaways of their own and lost receiver Breshad Perriman to a targeting hit early in the fourth quarter, but rallied to preserve the win.
Bortles said the injury wound up giving the team an emotional jolt.
"That's a brother," Bortles said. "That was on me a little bit for throwing that ball and kind of setting him up. We finished the game out for him. That gave us a little fire and a little extra motivation to win the game."
Trailing 13-7 in the fourth, Houston pinned UCF on its own 2, but the Knights got some space on a 17-yard completion from Blake Bortles to Perriman.
Bortles went to Perriman again two plays later, but his pass over the middle was broken up by Cougars' cornerback Zach McMillian. McMillian was flagged for targeting on the play, and was ejected after a review.
Perriman remained down on the field for several minutes receiving medical attention and was carted off.
The Knights weren't shaken, though, and Stanback scored his second touchdown of the game five plays later to stretch UCF's lead to 19-7 with 10:23 to play. The seven-play, 98-yard drive was the Knights' longest of the season.
Following a UCF missed field goal, Houston got life when O'Korn found Wayne Beadle in the end zone from 12 yards out to close the gap to 19-14.
UCF then gave the Cougars the ball right back with 3:02 to play after going three-and-out.
Houston went to the air and moved quickly, eventually using a 14-yard pass on third down by O'Korn to get into the red zone. But UCF held -- and held on to sole possession of first place.
O'Leary said he expected Perriman to be OK, but wasn't sure of his status for next week against Temple.
"He got sandwiched in there. That's what they call launching, they call targeting. He didn't target him, but he left his feet and hit him helmet to helmet," O'Leary said. "He left his feet and launched into the air. You got to keep your eye on the ball and he didn't do that."
Houston coach Tony Levine lamented his team's inability to capitalize on UCF's three turnovers.
"The thing we emphasize more than anything in our program, defensively, is creating turnovers," Levine said. "Normally, when you win the turnover margin you win the game."
After defense-dominated first half, offense began to pick up in the final 30 minutes.
Houston's first possession of the second half ended abruptly when Alexander intercepted a deflected pass by O'Korn.
But the Knights turned it right back over when Bortles fumbled after being sacked from behind.
The Cougars worked quickly and needed just four plays to set up a 24-yard touchdown run by O'Korn to put them up 7-6.
The Knights offense recovered, and capped a 10-play, 75-yard drive with a 15-yard touchdown run by Stanback to make it 13-7.
O'Leary wanted no talk about the Knights controlling their own destiny for a BCS bid with four games to go.
"You won't even hear me mention that," he said. "I'll be talking about Temple. We've got to get up each and every week and take care of one game at a time."