The Bulls became the third second-ranked team to lose in the last three weeks, having their unexpected unbeaten run snapped by tricky Rutgers 30-27 on Thursday night.
Third-string quarterback Andrew DePaola threw a 15-yard touchdown pass off a fake field goal to give the Scarlet Knights the lead in the third quarter and Rutgers also used a fake punt to set up a field goal in the first quarter.
Ray Rice provided a more conventional 181 yards on 39 carries for Rutgers (5-2, 2-1 Big East) and Mike Teel threw two touchdown passes to Tiquan Underwood.
"We just went out there and played our best football," Rice said.
The Bulls (6-1, 1-1) had their eight-game winning streak come to an end, no doubt to the delight of Boston College, LSU, Oklahoma and the rest of the teams hoping to grab the second spot in the BCS standings USF held this week.
Matt Grothe threw for 247 yards and a touchdown and ran for 58 yards, but Rutgers' defense swarmed South Florida's multitalented quarterback in the second half and sacked him seven times in the game.
A week after No. 2 California lost to Oregon State and two weeks after then-No. 2 Southern California was upset by Stanford, the Bulls became the 11th Top 10 team to fall to an unranked opponent this season.
Though Rutgers, which started the season ranked 16th, but fell out after two straight losses last month, might not be unranked much longer.
Jeremy Ito lined a career-long 51 yard field with 11:59 left in the fourth quarter to give Rutgers a 30-20 lead.
Grothe's gang wasn't done. He led the Bulls on a 70-yard touchdown drive that Mike Ford capped with a 1-yard run with 9:16 left to make it 30-27.
When USF linebacker Ben Moffitt recovered Rice's fumble near midfield with 4:11 left, the Bulls were in business at the Rutgers 40. But Damaso Renkart sacked Grothe on the first play, and the Bulls were forced to punt.
Rutgers was unable to kill the clock and the Bulls got one more shot to keep their perfect season alive, starting at the Rutgers 49.
On the first play, freshman Joe Lefeged came on a safety blitz and sacked Grothe from the blind side. On fourth-and-22, Amarri Jackson caught a pass down the sideline beyond the first down marker, but the play was wiped out by an offensive pass interference call because the receiver pushed off.
The last gasp came on a fourth-and-37 from the Rutgers 24. Grothe heaved a desperation pass into traffic and Rutgers defensive back Zaire Kitchen intercepted.
For the second straight season Rutgers came up with a huge victory on a Thursday night at home. Last year it was No. 3 Louisville, at the time the highest ranked opponent Rutgers had ever beaten.
Not anymore. This win set off another celebration, though not quite as wild as last year's after beating Louisville, with fans again flooding the field.
After reaching the rankings for first time in the 11-year history of South Florida football earlier this season, the Bulls shot up the charts behind a quick and hard-hitting defense and Grothe's dynamic playmaking.
In this topsy-turvy season, the Bulls' national title hopes can't quite be put to rest. But they took a major hit.
The Scarlet Knights, last season's surprise team from the Big East, gave their season a much-needed jolt.
With Rutgers up 20-17 midway through the third quarter, Rutgers defensive back Devin McCourty blocked a field goal to preserve the lead.
Rice and Teel responded with a drive that stalled at the USF 15. Ito came out to attempt a 32-yard field goal, but Rutgers coach Greg Schiano had something else in mind.
DePaola, the holder, took the snap and rolled right, barely avoiding a sack, and floated a pass into the outstretched arms of Kevin Brock. The tight end scooted into the end zone with 4:09 left in the third to give Rutgers a 27-17 lead.
"We haven't done a lot of that around here," Schiano said. "Thank God it worked."
Rutgers used a trick play on its first drive, too.
Ito lined up to punt but instead lofted a perfect pass over a USF defender to James Townsend for a 36-yard gain to the Bulls 13. That set up Ito's 26-yard field goal.
Rutgers scored more points than any team had hit up USF for this season and kept defensive end George Selvie, the nation's leader with 11.5 sacks, away from Teel.
USF hadn't allowed a runner to reach 100 yards in the 14 games since Rice went for 202 in the Scarlet Knights' 22-20 win last year. Rice had 94 at halftime Thursday night.
"When my number's called," Rice said, "I'm going to do whatever it takes."