University of Arizona's Adam Hall intercepts a pass intended for University of Oregon's David Paulson in the first quarter in November 2010.

Dean Knuth/Arizona Daily Star

EUGENE Ore. - Adam Hall was standing in the freezing rain, sore and exhausted, when he was asked to explain a devastating penalty.

"Which one?" he wondered.

On a night when the Arizona Wildcats were penalized 10 times for 80 yards, it was easy to get them confused.

The Wildcats (7-4 overall, 4-4 Pac-10) struggled to stay disciplined Friday against No. 1 Oregon, and it cost them. In part fueled by Arizona's mistakes, the Ducks posted 34 second-half points on the way to a 48-29 win at Autzen Stadium. With a win next week, UO (11-0, 8-0) can earn a spot in the BCS National Championship Game.

Arizona's players left Eugene about 4 a.m. Saturday impressed with the Ducks' offensive performance, but furious over a handful of mistakes. Though Oregon outscored the Wildcats by 19 points, it gained just 31 more yards.

"We had 500 yards of total offense," tailback Nicolas Grigsby said, "but we can't play against the refs and them, too."

Here's a look at four of the Wildcats' mistakes - and how they helped clear the way for an easy Oregon win:

Second quarter

• The situation: Oregon is facing third-and-three from midfield when Wildcats defensive end Brooks Reed stuffs running back LaMichael James for a 3-yard loss. Arizona, leading 16-14, appears destined to get the ball back.

• The call: Toward the end of the play, Hall tussles with a Ducks receiver and is flagged for a 15-yard personal-foul penalty. The UA safety insists he was merely fighting back after 1 1/2 quarters of rough play.

The receiver "had me by the face mask and (referees) said I retaliated," Hall said. "It was a judgment call."

• The result: The third-down play is nullified, and the Ducks advance to Arizona's 38 and are awarded a first down.

• The situation: Two plays later, Hall is called for another personal foul - this one coming after he hits James toward the end of a 1-yard run.

• The call: Referees claim Hall drilled James with a helmet-to-helmet hit and penalize him 15 yards, even though replays show Arizona's safety made a form-perfect tackle.

"It was probably one of the cleanest hits I've ever had," Hall said.

James exits the game with what is later diagnosed as an abrasion above his right eye. The tailback's version of events is a bit different.

"He hit me helmet-to-helmet," James said. "I really couldn't see out of my right eye."

• The result: The Ducks are awarded another 15 yards and a first down and advance to Arizona's 15. The Wildcats catch a break four plays later when running back Kenjon Barner - James' replacement - fumbles at the UA 8. Jake Fischer recovers, giving the Wildcats the ball back with a 16-14 lead.

Third quarter

• The situation: Oregon faces third-and-four from its 24 when quarterback Darron Thomas throws a seam pass to D.J. Davis. The ball is deflected, bringing up fourth-and-four.

• The call: Arizona's Anthony Wilcox is called for pass interference, even though he appears to turn around in time to contest the pass.

• The result: Oregon moves ahead to the 37 after the penalty, keeping the drive alive.

• The situation: Facing fourth-and-five at Arizona's 25, Ducks coach Chip Kelly sends out placekicker Rob Beard to attempt a 42-yard field goal. Beard misses it, giving Arizona the ball back trailing 20-19 with about five minutes left.

• The call: Arizona's Ricky Elmore is called off side just before the snap, negating the kick. On the visiting sideline, Stoops berates special teams coach Jeff Hammerschmidt for the defensive end's lapse in judgment.

"The guy wasn't even part of the rush," Stoops said. "It was just careless."

• The result: The Ducks gain 5 yards - and a critical first down - thanks to Elmore's mistake. Three plays later, Thomas rushes 20 yards for a touchdown to give the Ducks a 27-19 lead. Their drive goes 99 yards in 19 plays, equaling the longest in program history. Oregon converts on five third downs and two fourth downs before scoring.

"That was disappointing, too," Stoops said. "That was bad."

• The situation: Leading 34-22 after Thomas' 6-yard scoring pass to Davis, Oregon kicks off to Arizona's Travis Cobb. The Cats returner reverses field and is tackled at his own 11-yard line.

• The call: Arizona's return team is called for holding on the return, moving the Wildcats back to their 6 - half the distance to the goal line.

• The result: Backed into its own territory, Arizona goes three and out - its shortest drive of the game. Punter Keenyn Crier nets just 25 yards on his kick, giving the Ducks a first-and-10 at the UA's 35. The Ducks score in just seven plays, zooming out to a 48-22 lead that held.

"There were a few penalties that were a little problematic for us," Stoops said.