EUGENE, Ore. — It would be cliché to say that every game has one play that defines it.

But for the Arizona Wildcats, one play in Friday’s game against No. 1 Oregon was not only a defining moment of the game, but of the Wildcats’ season.

A 42-yard field goal attempt by Oregon kicker Rob Beard veered left past the upright, sparking a loud reaction from the Arizona sideline.

But the referee’s yellow penalty marker laid at the line of scrimmage. Arizona’s Ricky Elmore’s was flagged for an offsides penalty, giving the Ducks the five yards they needed to continue a drive that started on their own one-yard line.

Two plays later, Oregon quarterback Darron Thomas rushed 20 yards for the score, sucking the life out Arizona’s defense, and precious time off the game clock en route to a 48-29 Duck runaway victory.

“”That was costly. You can’t make that mistake,”” head coach Mike Stoops said after the game. “”That was disappointing, very disappointing. That guy wasn’t even part of the rush. Just careless. You can’t be careless, like I said, when you play a team like Oregon.

“”That was disappointing, just … it was just bad,”” Stoops said as he rubbed his eyes in frustration.

“”The 99-yard drive was a stop. Unfortunately, it was 18 plays and a missed field goal and then we have an offsides,”” said co-defensive coordinator Tim Kish. “”We shot ourselves in the foot a couple times.””

Up until that point, the Wildcats had been able to match the Ducks’ intensity, matching big play for big play and turnover for turnover.

Oregon would go on to drop 34 total points in the second half, compared to Arizona’s 10.

Failing to score touchdowns in the red zone, failing to take advantage of opponents’ mistakes, not getting off the field and, most of all, penalties were all symptoms of the Wildcats’ loss at Oregon, and have been present in all of Arizona’s losses this season.

The Wildcats were penalized 10 times for 80 yards, including two personal foul penalties on Adam Hall that sustained Oregon drives.

The Ducks were also 4-of-5 on fourth down conversions, including two successful conversions on the 99-yard drive that took more than six minutes off the clock in the third quarter.

“”I think we had some critical situations, third downs and fourth downs, where we could have gotten off the field and then (we) weren’t able to execute and get off the field,”” Kish said. “”That hurt us and that’s where we’re at.””

The one penalty snowballed into one play on one drive that not only gave the Ducks the clear path to steal the game’s momentum but also demoralized and tired out the Arizona defense.

The loss is the third in a row and marks the fourth Pacific 10 Conference loss for the Wildcats. In a year where Arizona’s Rose Bowl drought seemed like it had a chance to end, costly mistakes in critical situations will once again keep the Wildcats at bay.

“”Just for whatever reason we didn’t play it very well tonight,”” Stoops said. “”We just had too many mistakes.””

Arizona at Oregon notebook: What you missed

• Despite having 331 fewer rushing yards than Oregon, Arizona finished the game with only 31 fewer yards of total offense. Oregon had 537 yards while Arizona recorded 506 yards.
• Arizona quarterback Nick Foles passed for 448 yards on Friday, the fourth most in Arizona program history.
• Autzen Stadium saw an attendance of 59,990, the second largest crowd in the stadium’s history.
• Oregon’s mascot, The Duck, made two costume changes during the game. He first appeared dressed in a Santa Clause outfit, riding on a motorcycle to lead the Ducks out of the tunnel at the beginning of the game. The Duck then returned dressed as a present with a beak and duck feet before finally returning in its normal, green and yellow outfit.
• In an unusual move, Oregon head coach Chip Kelly made a previously recorded announcement asking for Duck fans to return to their seats five minutes before halftime ended to preserve the environment.