You just knew a Friday night #Pac12AfterDark game that began at 10:30 p.m. ET at Washington State could get weird. Sure enough, coach Mike Leach led his team to a surprising 30-27 win over No. 5 USC.

Many of the concerns about the Trojans heading into Friday night's game were validated. In addition to being a banged-up group, the offense, led by quarterback Sam Darnold, had myriad issues. The running game continued to struggle with additional injuries to the offensive line during the game. Outside of running back Ronald Jones' 86-yard touchdown, the Trojans averaged 2.75 yards per rush. Darnold felt the pressure often throughout the night, and USC's hopes ended on a Darnold fumble on their last possession.

Perhaps no stat was as telling as USC's three points off of two Washington State punts that went 17 and 19 yards, respectively. Those gave USC great field position and were turnovers for all intents and purposes. And yet the Trojans couldn't capitalize.

USC has been playing with fire on the offensive side of the ball for a while and the defense has been able to do enough to win. At some point, however, it felt like the Trojans were going to pay for their mistakes. Though the officiating from the Pac-12 refs wasn't kind to USC -- the offensive pass interference call on receiver Tyler Vaughns was as bad as you'll see this season -- the overall mental errors were too insurmountable.

Now USC has to regroup if it wants to stay in the College Football Playoff race. Washington State got its first win at home over the Trojans since 2002 (also 30-27). Here's what we learned from Friday's upset.

1. This USC team is officially a shell of itself: Not to blame the Trojans' performance on injuries, but the attrition this team is dealing with is definitely noteworthy. USC was already without linebacker Porter Gustin, wide receiver Steven Mitchell and offensive lineman Toa Lobendahn coming into Friday's game. In the first half alone, USC lost two more starting offensive linemen. Running back Ronald Jones was coming back from injury, and defensive tackle Rasheem Greene left the game late with an injury. The injured list is starting to read like a wartime infirmary:

Keep in mind that that the Trojans do not have a bye week for the rest of the season. Depth has already been tested, and it won't be the last time. And remember: depth doesn't simply mean the number of bodies. It means the number of capable bodies. Both can be issues.

2. The evaluation of quarterback Sam Darnold will be fascinating: As the amount of film on Darnold grows, so does the spotlight. That extra light shows a lot of good and bad things for Darnold, certainly enough to make him a polarizing and compelling prospect once he does turn pro (whenever that may be). There may not be a quarterback in college football -- at least not one of Darnold's status -- whose good so rapidly swings with the bad. The frequency of these changes is enough to give you whiplash. On one play in the first half, Darnold straight-up threw wide to an open receiver. On the next play, he showed good pocket presence by stepping up and expertly evading pressure before completing a pass. His lack of elite arm strength caused, or at least played a role in, his one interception on an out route. But he also did this ...

Congrats on earning a "sneaky athletic" label at the combine Sam Darnold pic.twitter.com/JzIcU31peg — Will Brinson (@WillBrinson) September 30, 2017

And then he led a clutch game-tying drive in the fourth quarter. He's at his best when the fate of the game is on the line. He's one of the premier signal-callers when he's making an off-balance play. Still, Darnold went 15-of-29 passing for 164 yards and averaged just 5.7 yards per attempt (though this was his first career game with two rushing touchdowns).

As mentioned above, the injuries along the offensive line don't lend any help. Every quarterback is as good as the protection allows them to be. Moreover, ESPN's game broadcast brought up confidence issues that Darnold has been working through. Those can be far more detrimental than footwork problems alone. Rolling out of the pocket and making quick throws was Darnold's best friend.

3. You're a good one, Mr. Grinch: The third-year defensive coordinator for Washington State hasn't received nearly enough credit for what he's done since arriving in Pullman, Washington. The numbers in total defense, seen below, have improved every year ...

Total defense is just one stat and not the most complete measure of a unit, but this does tell you how far Washington State has come on that side of the ball. Other than Jones' one long touchdown run and the first defensive series, the Cougars played well. It wasn't USC's entire A-squad, but the big picture is that defensive improvements have turned Washington State from simply a fun team to a legitimate top-25 one.

4. The Pac-12 North race just got a lot more interesting: Washington is the cream of the Pac-12 North until someone knocks the Huskies off. After Friday, Washington State may have a chance. Make no mistake: The win over USC doesn't suddenly make Wazzu a playoff team. This was not a sharp game by either side. Let's not forget the Cougars were at one point down 21 points to Boise State in the fourth quarter of a Week 2 game. This group has flaws. But if you have a proven quarterback -- Luke Falk certainly is -- you have a chance. The defense, as noted above, has improved and there's a real threat in the running game with Jamal Morrow. Add in the genius of Leach and that sounds like a team with a lot of good pieces. There's a lot of season left, but the Apple Cup at the end of the year may once again have major implications.