Everything you thought you knew about the Pac-12 heading into Week 4 wasn't true.

Well, unless you thought you don't know anything about the Pac-12. You don't.

The most surprising part of this weekend was that Utah comes out unscathed, joining UCLA and Cal as the only spotless teams left. That the Utes used a 63-20 win at Oregon to get to this point stands out most. Fittingly, head coach Kyle Whittingham had mentioned the cannibalism of the Pac-12 in his teleconference interview on Tuesday. 

Coincidence is only way to explain how that cannibalism occurred in Week 4.

The six intra-conference match-ups all went to the visitors, and the three most anticipated ended in outright blowouts Saturday night. South Division schools UCLA, USC, and Utah ripped through Arizona, ASU and Oregon, respectively -- and by a combined score of 160-64.

Utah, long considered on the cusp of competing for the South title, was desperate for a breakthrough win.

USC's loss to Stanford last weekend put their preseason goals in jeopardy. After two straight losses to the Sun Devils, they had redemption with a 42-14 blowout.

UCLA, which beat Arizona 56-30, had its back against the wall following a slim victory against BYU and the loss of one of the nation's best players, linebacker Myles Jack.

Not that the Wildcats, Sun Devils or Ducks wouldn't be motivated. But if there's any good news, it's that with things this crazy, those three squads can easily believe their chances haven't waned much.

Utah stamps legitimacy in Pac-12 South

With so many eyes focused on two matchups of Pac-12 South teams squaring off in Arizona, No. 18 Utah's visit to No. 13 Oregon might have been overlooked.

But the Utes (4-0, 1-0 Pac-12) won't be underestimated any longer after romping all over the Ducks, 62-20, behind quarterback Travis Wilson's best game.

Wilson threw for 227 yards, four touchdowns and no interceptions while completing 18-of-30 passes. He rushed six times for 100 yards and a score.

At the half: Travis Wilson has almost 3x as many rush yards as Freeman and almost 2x as many rush yards as Booker because... #Pac12AfterDark

— Chantel Jennings (@ChantelJennings) September 27, 2015

Recovering from a shoulder injury suffered in the Utah State game two weeks ago, Wilson hardly showed any tentativeness in a game he many didn't know he would play in. He threw for 137 yards in the first half to help Utah to a 27-13 lead. More impressively, considering the injury, Wilson rushed for 98 yards on five totes, the majority coming on a 60-yard dash that set up the final touchdown score with a minute left in the first half.

For the Utah defense to hold the Ducks (2-2, 0-1) to 20 points says enough about that side of the ball, but it's also worth noting the Utes continued their special teams excellence when punter Tom Hackett caught this high snap, then rushed for 33 yards on a designed fake. That set up Utah for a touchdown to go in front 48-13 in the third.

Odell Beckham, Jr., @TomHackett33. Same thing. #UTAHvsUO pic.twitter.com/5YLlfJIKz5

— Pac-12 Networks (@Pac12Networks) September 27, 2015

UCLA rides run game, this time behind big early lead

UCLA freshman Josh Rosen rebounded from a three-interception performance last week to lean on his running backs and rally to beat BYU.

Football coaches may see games as individual entities but seeing carry-over for a young quarterback can't be bad.

Like he did in the second half against BYU, Rosen didn't force things in his team's Week 4 victory. The ninth-ranked Bruins dropped No. 16 Arizona, 56-30, as Rosen completed 19-of-28 passes for two touchdowns and no interceptions. The Bruins (4-0, 1-0) ran the ball 45 times to 28 passing plays, surely because they got up on the Wildcats (3-1, 0-1) early, taking a 42-14 lead into the half.

Still, UCLA showed balance and got the backs beyond starting running back Paul Perkins going. He rushed 24 times for 85 yards and three scores, while Soso Jambo was hardly so-so -- the freshman rushed nine times for 96 yards and a score.

Spruce goes into the record books

Colorado senior receiver Nelson Spruce needed 59 yards to surpass Michael Westbrook's 2,548 career receiving yards, and he reached that mark in the middle of the second quarter, taking a quick-hit button-hook route for 11 yards.

Spruce finished with five catches for 80 yards on the day, and the next individual goal on the receiver's radar is the touchdown reception record. He remains three away from Westbrook's CU record of 22 career touchdown catches.

Other notables from the Buffaloes' 48-0 victory over Nicholls State were coach Mike MacIntyre's son, Jay, scoring his first career touchdown, and Colorado (3-1) piling up 358 rushing yards of total offense, including these 59 on a monster touchdown run by Donovan Lee.

Here's that 59-yard TD from @ItsDonovanLee21! Buffs up 38-0 with 4 minutes left in the 3rd Q. #GoBuffs http://t.co/m2yv1mI0hL

— Colorado Buffaloes (@cubuffs) September 26, 2015

McCaffrey's breakout game finally comes

Stanford fans saw something in running back Christian McCaffrey last season, even though the then-freshman never took more than 11 handoffs in a game and never rushed for more than 64 yards.

The sophomore hardly sniffed a 70-yard rushing game through the first two Cardinal games this season, but Stanford's offense has figured it out the last two games. McCaffrey followed up his first 100-yard rushing game in last week's big win against USC with a 206-yard, 30-carry performance in a 42-24 win Friday against Oregon State (2-2, 0-1).

That's not discounting the running back's danger in the passing game. On Friday, he recorded a catch for 38 yards.

Suddenly, No. 21 Stanford (3-1, 2-0) is back in the discussion as a Pac-12 North contender. McCaffrey's emergence, though it's come a little later than many hoped, didn't come too late.