Central Florida has replaced eighth-ranked Louisville as the team to beat in the American Athletic Conference and now looks toward earning the BCS bid that comes with the league crown.

The Knights quickly changed the landscape in the upstart conference by rallying to upset the favored Cardinals 38-35 on Friday night. With the win, UCF (5-1, 2-0) quashed Louisville's hopes of running the table toward another BCS appearance and possibly earning an outside shot at the national championship.

Though tied atop the AAC with Houston and South Florida, UCF's league title prospects got a big boost with the win that quarterback Blake Bortles called "giant" for the program and the school. The Knights want to continue the momentum and claim the rewards that Louisville was expected to reap.

"Obviously, it's a big win, there's no question about that," said UCF coach George O'Leary, adding that it was the biggest in his 10-year tenure at the Orlando, Fla., school.

"It's the biggest win of the year because it's a conference win. I'm just happy for the kids. We went in the game with one motto: great effort, great effort, great effort and compete. And that's what I thought they did."

Then came the wild celebration on the field and among a small section of Knights fans who chanted "UCF, UCF" after the improbable victory.

"I think it speaks volumes about this program," the quarterback said afterward in a jubilant locker room. "We are a gritty team, a resilient team. We came right back. I think that speaks a lot about our character."

Now comes the challenge of maintaining that character over the rest of the Knights' season.

UCF improved to 4-0 on the road this season, its best start in program history. The Knights' chances of securing the AAC's automatic BCS bowl berth depend on taking full advantage of friendly confines with four of their final six games at home, beginning next Saturday against Connecticut. The Huskies (0-5, 0-1) played at Cincinnati on Saturday.

With the exception of home games against Houston (Nov. 9) and rival South Florida (Nov. 29), the Knights' other four opponents are just 1-6 in conference play.

Though that record suggests a big advantage for them, they're taking nothing for granted.

UCF has already split two overtime games while scoring 50-plus points in each. The Knights upset Penn State on the road and fell a field goal short against South Carolina. They had to recover two fumbles in nine seconds to earn a comeback victory at Memphis.

The Knights now want to seize the huge opportunity they now have.

"This gives us great confidence," UCF receiver Jeff Godfrey said. "This will give us momentum."

The Knights' rally from a 28-7 deficit midway through the third quarter with 24 unanswered points matched the biggest comeback in school history. UCF overcame a 21-0 hole to beat Illinois State 28-24 in 1984.

But after Louisville reclaimed the lead, the Knights had to muster up a second comeback.

The Cardinals took a 35-31 lead on Dominique Brown's 15-yard touchdown run with three minutes left. Considering UCF used just under 7 1/2 minutes to tie the game earlier, there was more than enough time to mount a game-winning drive.

The Knights consumed 2:37, capping a 75-yard, 11-play drive with Bortles' 2-yard TD pass to Godfrey. Louisville QB Teddy Bridgewater and the Cardinals were unable to answer in the final 23 seconds.

Bridgewater's 50-yard desperation heave was batted down in the end zone as time expired, effectively ending his Heisman Trophy hopes as well.