TAMPA, Fla. -- In a game that pivoted on bold fourth-quarter conversions, Houston got the last and the biggest.

The Cougars converted a fourth-and-24 on the winning drive and received a 20-yard touchdown run from quarterback D'Eriq King to stun No. 17 South Florida with a 28-24 upset win on Saturday at Raymond James Stadium.

The Bulls (7-1, 4-1 American Athletic) had taken a 24-21 lead on a 30-yard field goal with 1:46 left, but the Cougars rallied to end the nation's longest winning streak at 12 games and deny the Bulls' hopes of a perfect season.

"We've got to drag them out in the water and fight them out there, put them in a game they haven't been in," Houston coach Major Applewhite said. "Our players did that, and our players finished. I'm really proud of our players."

After a 30-yard field goal by USF's Emilio Nadelman with 1:46 left, Houston got a 50-yard kickoff return from Brandon McDowell to shorten the field for a potential tying field goal.

King, easing into a larger role off the bench, threw a 30-yard pass to Courtney Lark on fourth-and-24 from the Houston 37. On third down at the USF 20 with no timeouts, simply wanting to shorten a tying kick, King scrambled in for the winning score.

"He brings a dimension to an offense that (USF QB) Quinton Flowers does," Applewhite said. "It's hard to contain those guys."

The Bulls saw their record streak of 24 straight games scoring at least 30 points come to an end. Houston (5-3, 3-2) won by avoiding the massive second-half collapses it had endured in the last two games.

Houston had rallied to tie the game three times in the second half, including a 2-yard run by King to make it 21-21 with 6:20 left. King had a 44-yard run to set up the touchdown for Houston, which rushed for 255 yards.

King finished with 83 rushing yards and two scores, and another 137 yards passing with a touchdown. Mulbah Car rushed for 137 yards and a score for Houston.

"We came out flat from the jump," USF linebacker Auggie Sanchez said. "We started out slow offensively and they picked it up, but defensively we came back in the second half and started off slow. That's not going to win you any football games."

USF had taken a 21-14 lead early in the fourth quarter when Flowers rushed in for his second touchdown of the night. Houston's defense took away Flowers' run game -- he had minus-9 yards when he scored his second touchdown -- but he still threw for 325 yards, including a career-best 186 to Marquez Valdes-Scantling.

Houston took the second-half kickoff and tied the game on a six-play, 75-yard drive, capped by a 39-yard touchdown pass from King to Lark.

USF answered, however, again going for it on a fourth-and-1 and getting a conversion from Darius Tice from the 8-yard line. Flowers kept it on the next play for a 3-yard touchdown run and a 14-7 lead.

Houston again tied the game, getting a 46-yard run from Car to set up a 4-yard touchdown run, sending a 14-14 tie into the fourth quarter.

Houston had been two very different teams in recent weeks -- it held Tulsa and Memphis to a combined seven points in the first half, but gave up 80 points in the second half of the two games.

Much the same way, Houston was able to hold USF to a 7-0 lead at halftime, helped by the Bulls going for it on fourth-and-short four times and converting only twice.

The Bulls twice went for it inside the Houston 30 in the first half, only to be stopped to turn the ball over on downs.

In the second quarter, Houston went for it on fourth-and-1 from its own 40 and was dropped for a loss. USF then went for it on fourth-and-1 at the Houston 28, with Tice converting with an 18-yard run. The Bulls went for it on the same drive on fourth-and-goal from the 2, getting a touchdown from D'Ernest Johnson.

USF's focus shifts to winning its division and playing for a first-ever conference championship, but it's a disappointing loss for a team that had sought an undefeated season.

"We just have to grow off this," Sanchez said. "If these are the guys we have, then I think we'll be OK."

NOTES: The two teams combined for 12 punts in the first half, going a combined 4-for-22 on third down and also turning the ball over three times on downs. ... Houston got very little from starting RB Duke Catalon, who was held to 23 yards on eight carries. ... USF came in leading the nation in turnover margin, but Houston minimized that by committing only one turnover, an early fumble. USF lost despite having no turnovers in the game.