LOUISVILLE, Ky. (AP) -- Louisville coach Bobby Petrino has gotten past the idea of style points.

Good thing. There wasn't much to go around following the seventh-ranked Cardinals' 23-17 win over Cincinnati on Saturday.

The nation's top offense struggled at times despite the return of quarterback Brian Brohm from a right thumb injury, and Louisville's 15th straight home win wasn't secure until cornerback Gavin Smart knocked down a pass in the end zone with 3 seconds left.

Still, the Cardinals survived. And for the usually picky Petrino, that's all that really mattered.

"It took until the last play to finish it, but we got it done," Petrino said. "I've learned that they're all going to be battles the rest of the way."

Brohm threw for 324 yards and a touchdown in his first game since injuring his throwing hand in a win over Miami on Sept. 16, but looked rusty at times. He threw a fourth quarter interception and had several balls float on him while his receivers dropped a handful of others.

"Maybe I wasn't quite as accurate, but I don't want to put that on the thumb," said Brohm, who completed 20-of-37 passes. "I made those throws all week in practice and should have been able to (today). ... We need to get our edge back and I think we will."

Cincinnati held the Cardinals (6-0, 1-0 Big East) 21 points below their scoring average and had a chance for an upset in the final seconds.

The Bearcats' Dustin Grutza threw for 129 yards and two scores and ran for 75 more, most of them coming on a frantic drive in the final two minutes. He led the Cincinnati (3-4, 0-2) to the Louisville 22 with 9 seconds left.

But Grutza's fourth-down pass to Earnest Jackson was broken up by Smart in the end zone as the Cardinals remained perfect.

"We had four chances to throw the ball in the end zone, you have to make the play," Cincinnati coach Mark Dantonio said.

Smart, at 5-foot-9 Louisville's shortest defensive back, said he didn't think about the implications as the ball floated toward him in the end zone.

"It just comes down to concentration," Smart said. "When (the quarterback) gets the ball out of his hand, you run to it and knock it down."

The Cardinals managed 429 yards of total offense, but had trouble gaining any sort of momentum as the Bearcats moved up and down the field behind a deliberate running game that piled up 212 yards.

"We can't throw the ball all over the place 50 times, we have to be two-dimensional," Dantonio said. "I thought Grutza played hard, tough. His leadership made you believe."

Brohm's return might have energized the crowd -- which roared when he entered the game -- but it failed to ignite the Louisville offense. The Cardinals converted just 3 of 11 third-down attempts and had trouble running the ball effectively. Louisville had just 105 yards on the ground and couldn't control the clock late.

"Anytime you don't put somebody away, you start worrying," Petrino said. "It's very worrisome looking at the scoreboard in the fourth quarter and knowing that two touchdowns will beat you."

It almost happened. After Louisville went up 23-10 on Art Carmody's third field goal of the day with 6:09 to play, the Bearcats responded with Grutza's 18-yard TD pass to Derrick Stewart with 4:10 left.

Louisville couldn't run out the clock, and Cincinnati then took over at its own 8 with 2:38 to go. The Bearcats moved 76 yards before the Cardinals held.

"It was nerve-wracking, but our defense did a great job," Brohm said. "Our defense put out a lot of fires today."

Doctors had originally told Brohm he would be out 4-6 weeks, but after what coach Bobby Petrino called an "amazing" recovery, he ran onto the stadium turf 27 days after surgery to repair a sprained right thumb.

Brohm led the Cardinals to the Cincinnati 29 on his first drive, the Bearcats stopped Louisville on fourth down.

The Cardinals then turned the ball over deep in their own territory on consecutive possessions, but the defense managed to hold the damage to a 23-yard field goal by Cincinnati's Kevin Lovell.

Louisville tied it at 3 on a 32-yard field goal by Carmody, but Cincinnati responded with a 17-play, 78-yard drive that took up more than half the second quarter. The Bearcats converted five third downs on the drive, which ended with an 8-yard touchdown pass from Grutza to Brent Celek.

Carmody added a second field goal to pull the Cardinals within four, and Louisville caught a break late in the half when Grutza and fumbled at midfield. Brohm led the Cardinals down the field, connecting with Gary Barnidge on a 1-yard touchdown pass to give them a 13-10 lead at the break.