Pac-12 Networks president Lydia Murphy-Stephans gave the hashtag a shout-out at Pac-12 media days in July, crediting it for unprecedented attention on the conference's football.
#Pac12AfterDark isn't relegated to nighttime. It's a state of mind that embodies the league's penchant for unpredictability. The conference's best games of the 2015 season's first half, regardless of kickoff time, were quintessential #Pac12AfterDark.
10. Stanford 41, USC 31 – Sept. 19
Left for dead after a 16-6 Week 1 at Northwestern, Stanford's return to Pac-12 prominence began with this dominant Week 3 performance at rival USC.
Quarterback Kevin Hogan called it the Cardinal getting back to “Stanford football” — in other words, a physical style owned on both lines.
The Cardinal had to rally from two separate deficits, bridging one just before halftime on head coach David Shaw's gutsy decision to attack the end zone in the final seconds.
9. Cal 34, Washington State 28 – Oct. 3
A first-down run on 3rd-and-36 in the fourth quarter helped Cal ice its come-from-behind win over Washington State, and running back Vic Enwere's play perfectly captures this game's essence.
It was a topsy-turvy contest, beginning with Washington State's two-score lead early and Cal's subsequent rally. Jared Goff added to his growing Golden Bear legacy with four touchdown passes to power Cal to a key victory for early Pac-12 North positioning.
8. Michigan State 31, Oregon 28 – Sept. 12
Some of the shine has come off this one, arguably the most anticipated non-conference game of the 2015 slate entering the season. But while Oregon's tumble from atop the national stage removes the College Football Playoff implications so many expected of this one, the game itself lived up to the billed intensity.
Michigan State's vaunted defense snuffed Oregon at the goal line, a play that proved instrumental in the Spartans' win.
Ducks quarterback Vernon Adams nearly engineered a winning drive, which would have carved a special place in Oregon football history for the FCS transfer — in large part because he was playing with a broken finger on his throwing hand.
7. Utah 24, Michigan 17 – Sept. 3
Utah's rise from relative obscurity to the thick of the College Football Playoff hunt began Week 1. The Utes spoiled the debut of Michigan head coach Jim Harbaugh, who would otherwise be unbeaten were it not for a botched punt this past weekend.
While Utah held on for a seven-point win, its performance was much more commanding. A Gionni Paul personal foul set up Michigan's first score of the night, nearly midway into the fourth quarter.
That imposing defensive effort foreshadowed the season to come for these still-unbeaten Utes.
6. Utah 34, Arizona State 18 – Oct. 17
In much the same fashion, the final score of Utah's Week 1 win over Michigan doesn't convey how dominant the Utes were, a 16-point win against Arizona State fails to accurately portray how close the Sun Devils were to pulling off an upset.
A rain-soaked Saturday night in Salt Lake City provided the weirdness for #Pac12AfterDark. Arizona State, already sporting a road upset in conference play and owner of a 12-game win streak against Utah, used aggressive defense and explosive special teams play to put a fright into the Utes.
Utah had a cumulative rushing output of -21 yards when Heisman Trophy candidate running back Devontae Booker broke the game open with the first of two, fourth-quarter touchdowns.
5. Cal 45, Texas 44 – Sept. 19
Cal nearly coughed up a two-score lead late in its visit to Texas, but the Longhorns suffered a baffling miss on the would-be game-tying PAT attempt.
To get a sense of just how unpredictable this season has been, Nick Rose's PAT gaffe isn't the most confounding special teams failure of the first half. It's arguably not even Texas' biggest special teams blunder.
The win in Austin scored Cal a measure of revenge for 2004, when the Golden Bears were passed over for their first Rose Bowl berth in a half-century in favor of the Longhorns. Then-Texas head coach Mack Brown's politicking helped the Longhorns receive the at-large bid to the Granddaddy of 'Em All.
4. Arizona State 38, UCLA 23 – Oct. 3
Arizona State's defeat of UCLA in the Rose Bowl isn't the largest upset of the Pac-12 season thus far – not from a point-spread perspective, at least. That distinction belongs to Washington, a 17-5-point underdog in its 17-12 win at USC.
However, from the perspective of the Pac-12 championship race, the Sun Devils threw the South into chaos ahead of schedule.
Arizona State was treading water when it visited Pasadena, already sporting a pair of lopsided losses to Texas A&M and USC. A second in Pac-12 South play and third overall may well have sent the Sun Devils spiraling.
Instead, Arizona State overwhelmed UCLA's freshman phenom quarterback Josh Rosen and stifled the typically sound Bruin run game. Kalen Ballage's victory-sealing touchdown run in the late fourth quarter after UCLA head coach Jim Mora took a voluntary safety goes down as one of the most exciting plays of the Pac-12 season's first half.
3. Utah 30, Cal 24 – Oct. 10
Just as I'm sure everyone predicted, the Pac-12's last two remaining unbeaten teams come Week 6 were Utah and Cal. And, as we all certainly anticipated coming into this marquee showdown, Cal's Goff threw five interceptions to just two touchdowns.
Wait – what?
Utah preserved its unblemished record in this Top 25 matchup by relying on its two cornerstones: defensive takeaways and big plays from Booker. The running back went off for 222 yards rushing, 45 receiving and a pair of touchdowns to pace a Utah win.
2. UCLA 24, BYU 23 – Sept. 19
The last play of UCLA linebacker Myles Jack's illustrious college career was, fittingly, a game-saving interception.
Jack tore his ACL a few days after sealing UCLA's come-from-behind win over BYU, then announced his departure for the NFL draft a week later. There's something poetic about his last play as a Bruin winning a game.
The other catalyst of UCLA's defeat of BYU was running back Paul Perkins, who tallied 219 yards – and wasn't even in on the game-winning push. Nate Starks concluded UCLA's comeback from down 20-10 with 60 yards on four straight plays, culminating in a touchdown run.
1. Washington State 45, Oregon 38 (2OT) – Oct. 10
In Mike Leach's four years as Washington State head coach, the Cougars have typically been good for at least one huge, road upset.
In 2013, they beat USC and Arizona away from the Palouse. Last year, it was Utah. The 2015 Cougars have plenty more opportunities to be the rude guests of the Pac-12, but already spoiled one party at Autzen Stadium.
Quarterback Luke Falk passed for five touchdowns and rushed for a sixth, half of which came either in one of two overtimes or with just one second remaining in regulation.
Falk's efforts, and a stingy defensive performance in the final quarter, helped Washington State rally from a 31-21 deficit to win. It was the Cougars' first victory in the series since 2006, and the best game of the first half of the 2015 Pac-12 season.
(Top photo courtesy of Getty Images)