Oregon's precipitous slide and Washington's rise highlighted the opening half of the Pac-12 season. Colorado and Utah could shape the finish.
The Ducks and the No. 5 Huskies had last week off but the last time they played it was against each other, and undefeated Washington romped 70-21 at Autzen Stadium. The victory ended Washington's 12-game losing streak to rival Oregon.
The game illustrated the rise of the Huskies, off to their best start (6-0, 3-0 Pac-12) since 1992, and the quick fall of the Ducks, who played for the national championship two seasons ago but have dropped four straight to sit at the bottom of the Pac-12 North (2-4, 0-3.).
With a nine-game winning streak dating back to last season, the Huskies host Oregon State on Saturday. The Ducks will visit Cal on Friday night.
Washington coach Chris Petersen said the task at hand now is keeping the players focused on the next game - and off the hype that comes with the undefeated start and the national ranking.
''It really is hard. With all the stuff outside, there are just so many outside influences. As much as you know, you probably still don't know how much is coming at these kids from all different directions with everybody. Human nature is what it is,'' Petersen said. ''We're foolish to think that doesn't have an effect on our team and our mindset. That's one of the big battles that we have as a team, as a coaching staff, is to keep these guys focused on being focused.''
Depending on how the season shakes out, Washington could be the first North team besides Stanford or Oregon to play for the Pac-12 title since the league championship game was created in 2011.
It could also be that the season-ending rivalry game between Washington and Washington State (which is also undefeated in conference play) in Pullman has some big-time implications.
EXPANSION SUCCESS: Colorado and Utah, which joined the Pac-12 when it expanded in 2011, don't want to finish as footnotes again in the South this season. The Utes and Buffaloes sit atop the division standings with 3-1 records, ahead of USC with two losses.
While Utah has seen a steady rise with its hard-nosed defensive play in recent years, the Utes have never made it to the Pac-12 championship game. After a 6-0 start last season, Utah was hurt by a 2-3 stretch.
Colorado is the more dramatic upstart in the south at 5-2 and vying to become bowl eligible for the first time since 2007. The Buffaloes are coming off a 40-16 rout of Arizona State last weekend and head to Stanford on Saturday.
Earlier this month, Colorado made its first appearance in the AP Top 25 since 2003. While the team has since dropped out, the Buffs are still getting enough votes to stay close.
''Our goal is the Pac-12 championships, like everyone else in the Pac-12. Just the bowl game, that would be nice. That would be nice. But that's not what we want, that's below what we want,'' Colorado outside linebacker Jimmie Gilbert said. ''Our goal is to shoot for the stars. If we reach them, that's what we want. If not, we tried.''
If the two teams are able to keep winning, the Rumble in the Rockies could decide the Pac-12 South.
QUARTERBACK WOES: This is the point in the year when injuries start taking a toll. This is especially apparent at Oregon State, which is down to its third-string quarterback, Marcus McMaryion, after injuries last weekend to starter Darell Garretson and backup Conor Blount.
It's so bad that a member of the coaching staff, former Utah State quarterback Chuckie Keeton, is serving as the scout-team QB.
Arizona finds itself in a similar position with quarterbacks Anu Solomon and Brandon Dawkins hurt.
The Wildcats started 17-year-old freshman Khalil Tate at QB in a 48-14 loss to USC last week and when he struggled, they turned to third-string TE Matt Morin. He hadn't played QB since high school five years ago and just started practicing at the position in the last two weeks.
''I don't know what our quarterback situation is going forward,'' said Arizona coach Rich Rodriguez, who is looking forward to a much-needed bye this week. ''But we've got at least two weeks now to figure something out.''
WHO YA GONNA CALL?: Injuries at other positions have forced No. 19 Utah to get creative. The team was so thin at running back that the Utes coaxed Joe Williams out of retirement last week to help against Oregon State.
Williams, who left the team after the second game of the season, ran for 179 yards and a touchdown in the Utes' 19-14 victory over the Beavers.
HEISMAN HOPEFULS: Just one name really sticks out in the Pac-12: Washington quarterback Jake Browning. The sophomore has thrown for 1,418 yards and 23 touchdowns, with a 72.2 percent completion rate. In the game against Oregon, he threw for six touchdowns and ran for two, matching the Pac-12 single-game record.
Stanford's Christian McCaffrey, last season's AP Player of the Year and the runner up for the Heisman Trophy, did not play last weekend against Notre Dame because of an injury. His status for the game against the Buffaloes is not yet known .
McCaffrey is averaging 104 yards a game this season, ranked No. 24 in the nation.
AP Sports Writers John Marshall in Phoenix and Pat Graham in Denver contributed to this report.