University of Arizona's Nick Foles gets sacked as he cannot convert on fourth down with University of Oregon's Dion Jordan, right, in the fourth quarter at Arizona Stadium on September 24, 2011 in Tucson, Ariz.

Dean Knuth/Arizona Daily Star

Arizona's task Saturday night was tough enough.

The No. 10 team in the country was in the house, boasting one of the nation's best offenses and enough playmakers on defense to make any coach nervous.

The last thing the Wildcats needed to do was make the task any more difficult.

That's precisely what Mike Stoops' squad did in the first half, however.

On Oregon's first play from scrimmage, quarterback Darron Thomas faked a handoff and started to take off down field. He was dragged to the ground by Arizona's Lamar De Rego, making his first career start, and the junior defensive end was flagged for a 15-yard personal foul penalty for a horse-collar tackle.

That was just the start of it.

Arizona committed eight penalties for 76 yards in the first half including four 15-yard personal foul penalties. The Wildcats committed just three penalties for 25 yards in last week's 37-10 loss to Stanford.

"The first half was frustrating and humiliating in some ways," Stoops said. "We have to start the game better. We are not a mature team at times."

The eight flags were the most by Arizona in a half this season. The Wildcats' previous high was six, coming in the first half at Oklahoma State.

The Wildcats also set themselves back with dropped passes. Juron Criner dropped two Nick Foles passes, and David Roberts also had a costly drop in the first half.

Zendejas returns

Senior place-kicker Alex Zendejas converted his first field goal attempt of the season when he nailed a 28-yard attempt in the first quarter.

Zendejas served as Jaime Salazar's backup the first three games of the season but was inserted as the starting kicker after Salazar went just 1 for 4 on the season.

The senior didn't have a perfect night, though. His extra-point try after Arizona's first touchdown was blocked. He converted his other point-after tries.

Secondary fill-ins

Arizona figured to have a strong secondary this season with Trevin Wade and Jonathan McKnight manning the cornerback spots and Adam Hall and Marquis Flowers controlling the safety spots.

On Saturday, Wade was the only one who saw the field.

Flowers, the Pac-12 Conference's leading tackler heading into the game, missed the matchup with an undisclosed injury after starting the first three games of the season.

Hall tore his ACL during spring practice, and McKnight tore his right before the season began.

Extra points

• Wide receiver David Douglas had his first 100-yard game of his career, catching seven passes for 120 yards in the loss

• Sophomore left guard Chris Putton was injured in the second quarter on a third-and-long where quarterback Foles was sacked. Junior Shane Zink replaced Putton for the rest of the game.

• All of Oregon's scoring drives were under three minutes. The longest scoring drive was the Ducks' first, an eight-play, 80-yard drive that took 2 minutes 42 seconds.

• Arizona's 35 rushing attempts were the most by the Wildcats this season. Their previous high was 23 against Stanford.