Before we completely close the door on Week 9, it's worth taking a look back at some of the memorable games -- and three of them in particular were extremely memorable.

Two of the Pac-12's top-10 teams fell on the road to unranked opponents (one of which is now ranked) and a last-second field goal by a true freshman kicker may have altered the entire landscape of the Pac-12 South.

So of the following three games, which was the most significant?

Your options:

Arizona over USC: The win sent shockwaves throughout the division and USC -- once viewed as untouchable, at least in the South -- is in jeopardy of not even making the conference championship game. Arizona, on the other hand, looked sensational. True, they gave up 345 receiving yards to Marqise Lee. But the defense is finally starting to catch up to the offense, just enough, to keep the Wildcats in games.

UCLA over Arizona State: The other game that sent ripples through the South has to go down as one of the best games of the year in the conference. Arizona State jumped out to a 14-0 lead, but the Bruins battled back. We saw Brett Hundley mature before our eyes on that final drive that set up a last second field goal from Ka'imi Fairbairn. ASU quarterback Taylor Kelly had one massive mistake -- but was really solid the rest of game, leading his team on a go-ahead drive at the end of the game. When we look back at some of the best matchups of the 2012 season, this one should be up there.

Washington over Oregon State: With Oregon State's loss, there is now just one undefeated Pac-12 team left in the conference. That's two undefeateds that the Huskies have knocked off this season. While the offense didn't get back on track like Steve Sarkisian had hoped, it was a gritty effort from the defense to nab four interceptions and some good, hard running from Bishop Sankey against one of the top rushing defenses in the country. The Huskies broke a three-game losing streak with the win and it was a confidence builder as they prepare to close out the final four weeks against unranked teams. Anyone else think this game jump-started a five-game win streak for the Huskies?