Here are five things to keep an eye on this week in the Pac-12.
The North remembers: There are four undefeated Pac-12 teams going into Week 5. By the end of it, at least one will have a loss. Undefeated Stanford and Washington square off in a battle that has tremendous implications within the North Division, the conference as a whole and, potentially, the College Football Playoff.
Both teams were pushed to the brink on the road last week, with Stanford scoring a last-minute touchdown to overcome UCLA and Washington needing overtime to escape Arizona unscathed.
Both are highly effective in all three phases of the game. Per ESPN Stats & Information, only three FBS teams rank in the top 20 in offensive, defensive and special teams efficiency. Two of them are Stanford and Washington (Michigan is the third). They've taken different paths en route to perfect starts, though. The Cardinal (3-0) have played the third-hardest schedule so far, according to ESPN's FPI metrics. Washington (4-0) has played the 110th-hardest.
Key matchups to watch are Stanford's beat-up secondary against Washington's explosive wide receivers and Washington's front seven against Christian McCaffrey. UCLA did a good job keeping McCaffrey out of the end zone and avoiding him on special teams last week, but McCaffrey still managed 138 yards on 26 carries for an average of 5.3 per carry.
Fourth-and-fantastic: The fourth quarter treated Pac-12 fans to some pretty good football last week (or bad, depending on which team you cheer for). Stanford and Utah had last-minute touchdowns to lock up wins over UCLA and USC, respectively. Arizona State scored 31 fourth-quarter points against California. Arizona forced overtime against Washington. Colorado had a late, game-clinching interception against Oregon. All five conference games last week had fourth-quarter drama. This trend could make Arizona State-USC particularly exciting. The Sun Devils have forced all five of their turnovers in the fourth quarter, and USC is coming off a last-minute loss.
Chess match in Pasadena: UCLA head coach Jim Mora wasn't shy about sharing his concerns about Arizona quarterback Brandon Dawkins, saying that when Dawkins is in the game, it's like Arizona has a Wildcat quarterback (no pun intended) who can also throw the ball. Dawkins is second in the Pac-12 in rushing with 391 yards and seven touchdowns, but he's also completing 61.7 percent of his throws with three touchdowns and one interception.
This sets up a fun chess match between Rich Rodriguez's offense, which averages 30.5 points per game, and UCLA's defense, which allows 22 points per game. While the Bruins did allow McCaffrey to rush for 138 yards last week, they kept him out of the end zone, which most teams would consider a win. Expect UCLA linebacker Jayon Brown, who is extremely quick, to spy Dawkins most of the game. Brown is third in the Pac-12 with 33 tackles heading into this game.
Where they want to be: Oregon State is going through a difficult rebuilding process. The Beavers haven't won a conference game since beating No. 6 Arizona State in 2014. That's 11 straight losses. Colorado, meanwhile, seems to be emerging from the dark tunnel of its cultural renovations. After winning just one conference game the past two seasons (against Oregon State in 2015) and going 2-25 in Pac-12 play in Mike MacIntyre's tenure, the Buffaloes scored the program's first signature win of the Mac era last week by topping Oregon 41-38. Oregon State head coach Gary Andersen this week praised MacIntyre's efforts, saying there is no greater reward for a head coach than to flip a program the way he has. "They are playing a brand of football there that they haven't seen in years," Andersen said.
Intriguing rematches: Last year's showdowns between Utah-Cal and Oregon-Washington State provided plenty excitement. Last year's game between the Utes and Golden Bears was a College GameDay matchup. The Utes intercepted Jared Goff five times and forced six total turnovers, but squeaked out a 30-24 win. This season, those opposite styles of high-powered offense (Cal) and stingy defense (Utah) will clash again. The Bears average 45.5 points per game, and the Utes are allowing just 15.8. The twist? Utah's offense is starting to catch up to its defense. While Cal's Chad Hansen leads the Pac-12 with six receiving touchdowns, Utah's Tim Patrick isn't far behind with five.
Up north in Pullman, the Cougars will go for their second straight win over the Ducks after pulling off a double-overtime stunner last season in Eugene. Washington State should be well-rested coming out of a bye week. Meanwhile, Oregon has lost consecutive games in a season for the first time since 2007. The Cougars haven't beaten the Ducks in consecutive years since the 2002 and 2003 seasons.