The Core Four — what I’m calling Oregon, UCLA, Utah, and USC — all handled their business this past week while facing varying degrees of adversity. That group is 15-0 against the rest of the Pac-12 this season. We have separation at the top of the league, and we’re barreling toward what could very well be one of the most exciting weekends (Nov. 19) the Pac-12 has seen in some time.

Let’s dive into this week’s updated Power Rankings. Little changed at the top, but the bottom half shuffled a bit.

12. Colorado Buffaloes

Prev. rank: 12

Colorado fans thought there was a chance the defense could get right in Saturday’s contest against Arizona State. Instead, the Buffs got burned by a resurgent ASU pass game in a 42-34 loss. Colorado will be happy to be done with the Arizona schools this season. With Trenton Bourguet taking over at quarterback for the Sun Devils and throwing for 435 yards, two of the eight most prolific pass days by CU opponents in program history have happened this year. (Arizona’s Jayden de Laura threw for 484 earlier this year.) Colorado is playing with energy under Mike Sanford, it just has a long way to go.

11. Cal Golden Bears 

Prev. rank: 11

I don’t want to pile on, as I’ve been pretty critical of Cal in recent weeks. It’s just not a very strong team. Oregon’s offense is eviscerating everyone right now, so that piece of it is what it is for Cal’s defense. But the offense can’t protect quarterback Jack Plummer, and when Plummer has gotten time, he’s thrown some pretty ugly interceptions. The Bears have lost four straight games now and are facing a very real possibility they miss a bowl game. It’s at USC this week, then at Oregon State next week, then UCLA at home to close out the year. If those three are all indeed losses, the Bears will have their worst season since 2013.

10. Stanford Cardinal

Prev. rank: 8

Another poor team. My biggest concern with Stanford entering the year was at the line of scrimmage. It has been a resounding failure there on both sides of the ball. UCLA sacked quarterback Tanner McKee four times and made his life miserable even on plays where they didn’t. The UCLA run game went for 351 yards at 8.4 a carry (adjusted for sacks) against the Stanford front. I wasn’t convinced by the Notre Dame win. I was even less sold after the ASU win. A 38-13 loss to UCLA was why.

9. Arizona Wildcats

Prev. rank: 9

Arizona is what it is — an offense that’s wonderful and a defense that’s a liability. The Trojans were missing a number of key starters, offering an opportunity for Arizona to catch USC. It almost did. The game — a 45-37 loss — played out exactly how everyone expected. Arizona scored points, just not enough. That’s been the theme of the season.

8. Arizona State Sun Devils

Prev. rank: 10

In two appearances, Trenton Bourguet has engineered 80 points. In the other five FBS games ASU has played this season with Bourguet standing on the sidelines, the offense has scored 90 points. Total. Either the fourth-year quarterback is one of the worst practice players of all time or the ASU coaching staff was completely ignoring the offense during the week. Interim coach Shaun Aguano took over play-calling duties in ASU’s 42-34 win over Colorado and the offense found life. Bourguet threw for 435 yards and three scores while completing 74% of his passes. In his first career start, he hit his first eight throws and led back-to-back scoring drives to open. He’s the starter. End of discussion.

7. Washington State Cougars

Prev. rank: 7

Coming off a bye week… At home… Facing a backup quarterback making his first career start… Washington State just has to be sick to its stomach knowing it let a golden opportunity slip away this past Thursday. The Cougars fell 21-17 to a Utah team missing not only its star quarterback but each of its top two running backs and its best pass-catcher. The inability to give quarterback Cameron Ward consistent protection is the biggest issue facing Jake Dickert at the moment.

6. Washington Huskies

Prev. rank: 6

The Huskies were on a bye week this week, so this section is too.

5. Oregon State Beavers

Prev. rank: 5

The Beavers were on a bye week this week, so this section is too.

3. USC Trojans

Prev. rank: 4

In a tie for the No. 3 spot, we have a pair of teams who were separated by a single point two weeks ago who came out this past weekend and both pulled off impressive performances while missing important stuff. Utah was missing its starting backfield against Washington State. USC was missing half its linebacker rotation and its top two receivers against Arizona. I think USC’s win was more impressive… I think? Let me put it this way: I’m less concerned about USC’s injury situation than Utah’s, so I can justify moving the Trojans up into a tie for third, but I still value the Utes’ head-to-head win that just happened so I refuse to swap them.

3. Utah Utes

Prev. rank: 3

This season for Utah is turning into a meat grinder. Cameron Rising is banged up, essentially sidelining himself at the last second before the Utes kicked off against Washington State. Star tight end Brant Kuithe and reserve running back Chris Curry are lost for the season already, and tight end Dalton Kincaid appeared to do some damage to his shoulder before exiting in the third quarter. Last year’s 21-touchdown man, Tavion Thomas, is in limbo. His backup, Micah Bernard, was limited to three touches on Thursday, attempting to give it a go after initially being said to be unavailable, only to leave the game and not return. With Curry out as well, Utah could be on its third-string tight end and its fourth-string running back depending on how the next week goes. Defense played well, though…

2. UCLA Bruins

Prev. rank: 2

Zach Charbonnet is a monster. Dorian Thompson-Robinson didn’t have to do much. UCLA’s defensive front feasted on Stanford’s offensive line. The Bruins took care of business. They scored 24 unanswered points in the game and at one point held a 38-6 fourth-quarter lead. They did what great teams do: dominant when you’re supposed to dominate. No hangover from the Oregon loss. UCLA keeps chugging along.

1. Oregon Ducks

Prev. rank: 1

What can be said about Bo Nix that hasn’t already been said? He had six touchdowns for the Ducks, his fourth game this season with five or more scores. If he’s playing like this, Oregon is one of the best teams in the country. I couldn’t care less about an interception on a heave at the end of the half or an interception that bounces off his receiver’s hands and falls into the lap of a defender. The Ducks are up to fifth nationally in points per game and they’re getting better each time out. Dan Lanning’s squad is the class of the conference at this point.