TUCSON — Forget those heady dreams of a Bowl Championship Series title.
The Pac-12 Conference South division championship is now far from a sure thing.
And that sold-out showdown coming up against unbeaten Oregon?
The only luster might be a reflection off the Ducks' helmets.
"Our mistakes," Coach Lane Kiffin said, "caught up with us."
On a day when USC produced 618 yards of offense and quarterback Matt Barkley and receiver Marqise Lee set records, the Trojans were unable to overcome five turnovers, 13 penalties and an Arizona team out to give first-year Coach Rich Rodriguez a signature victory.
USC, which began the season ranked No. 1 in several polls, fell to 6-2 overall and 4-2 in conference play.
"We didn't show up," linebacker Dion Bailey said as he walked off the field. "We didn't play well enough and we lost."
USC players had vowed not to repeat the mistake-filled formula that helped lead to their undoing in a September defeat at Stanford.
They survived their errors in victories over California, Utah, Washington and Colorado and climbed to ninth in the BCS standings. With solid play and victories — and a few losses by teams ahead of them — the Trojans were regarded as a team that might make a run to the title game, especially if they knocked off Oregon.
But those dreams fell apart against an Arizona team that lost an early 10-point lead and then came back from a 15-point third-quarter deficit to beat the Trojans.
"I hope," Rodriguez said, "it makes people notice."
Arizona, led by multidimensional quarterback Matt Scott, rolled up 588 yards to improve to 5-3 and 2-3 in the Pac-12.
Kiffin said last week that he hoped the Trojans had "hit rock bottom" in regard to penalties. But the Trojans cratered against the Wildcats and lived up to their billing as the most penalized team in college football. Personal fouls stalled USC's early drives and extended Arizona's, and the Trojans had amassed 117 penalty yards by game's end.
"Penalties killed us," said Lee, who caught 16 passes for a conference-record 345 yards. "You can't come to a game, have over 100-something yards in penalties then have turnovers and expect to win. Especially when you're away."
USC, which lost three fumbles, looked like it might get away with it again as Barkley passed for a school-record 493 yards, with three touchdowns, and Lee made spectacular catches and kick returns.
After trailing 10-0 at the end of the first quarter, the Trojans came back to take a 21-13 lead by halftime.
USC increased the margin to 28-13 on Lee's 44-yard touchdown reception. It looked like the Trojans might put the game out of reach when an Arizona defender fell down and receiver Robert Woods broke free along the left sideline.
But Barkley's pass sailed out of Woods' reach.
"I'll be thinking about that play all night," said Barkley, who completed 31 of 49 passes, with two interceptions. "I got a little too excited seeing how wide open he was and just didn't put enough air under the ball."
Arizona took advantage, Scott rushing for a touchdown and passing for another, and running back Ka'Deem Carey rushing for one more to put the Wildcats ahead, 32-28, early in the fourth quarter.
Arizona went ahead by 11 on Scott's touchdown pass to receiver David Richards with 5:36 remaining.
Lee's 72-yard kickoff return set up a touchdown run by Silas Redd, and Barkley's two-point conversion pass to Lee pulled the Trojans to within three points with 4:40 to play.
But Arizona ran for two first downs, forcing USC to burn its last two timeouts, and the Trojans did not get the ball back until only 55 seconds remained.
Barkley passed twice to the middle of the field to Redd and once to Lee, failing to stop the clock while moving to Arizona's 48-yard line, too far for Andre Heidari to try a field goal.
On the game's final play, Barkley heaved a pass into a crowd in the right corner of the end zone. Lee leaped, and got a hand on the ball, but it fell incomplete.
"Those are kind of throw-up plays, literally and figuratively," Barkley said. "I don't think it should have come down to a play like that in the first place."