Honestly, if you looked at the Mountain West standings back in August, nobody saw the 2025 season ending the way it did. The matchup between Colorado State vs San Diego State football was supposed to be a standard mid-season clash. Maybe a bit of drama, sure. But what we got instead was a complete dismantling of the status quo that ended with one coach getting his flowers and the other getting his walking papers just two weeks later.
The October 3, 2025 meeting at Snapdragon Stadium wasn't just a win for the Aztecs. It was a 45-24 statement.
It was a statement that Sean Lewis’s "AztecFAST" offense had finally arrived, while the "Air Raid" era in Fort Collins was officially on life support. By the time the clock hit zero, the Rams were staring at a 1-4 record, and the writing was on the wall for Jay Norvell.
Why the 2025 Colorado State vs San Diego State Football Game Changed Everything
Most people look at a 21-point loss and think, "Yeah, they got beat." But it was how it happened. San Diego State hadn't looked that explosive in years. They scored touchdowns on four straight drives in the first half. Four. Straight.
Jayden Denegal, the Aztecs' quarterback, looked like a different human being. He threw for 256 yards and two scores, while Jordan Napier was basically playing a different game than the Rams' secondary, hauling in 153 yards. It was surgical. It was fast. It was everything Sean Lewis promised when he took the job.
On the other side, Colorado State looked lost. Jackson Brousseau tried to keep them in it, and that 49-yard bomb to Armani Winfield was pretty, but the Rams couldn't stop a nosebleed. They trailed 28-10 at half and never really threatened again.
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The Fallout in Fort Collins
You’ve gotta feel for Jay Norvell in a way, but the results just weren't there. Two weeks after this loss, following another defeat to Hawaii, Colorado State fired him. He finished with an 18-26 record. The irony? His 2024 season was actually great—8-5 and a bowl game. But college football in 2026 doesn't care about what you did last year.
With the move to the Pac-12 on the horizon, the CSU administration decided they couldn't risk entering a new era with a program that was trending downward.
A Deep Look at the Series History
If you're a history buff, this rivalry is actually way more lopsided than you’d think. Before the 2025 blowout, the Aztecs already held a significant lead in the head-to-head series.
- Total Record: San Diego State leads 23-15.
- The 2025 Outcome: SDSU 45, CSU 24.
- Last Rams Win: A narrow 22-19 victory in 2023 at Fort Collins.
- The Ugly Streak: From 2009 to 2015, the Aztecs won five straight.
San Diego State has traditionally been the bully of this matchup. Even in years where the Rams have a high-flying offense, the Aztecs usually find a way to muddy up the game or, in the case of 2025, just outpace them entirely. The 2016 game is still a weird fever dream for Rams fans—they won 63-31 in San Diego. But that’s the outlier, not the rule.
What Most People Get Wrong About This Matchup
There’s this weird misconception that Colorado State is the "offense" school and SDSU is the "defense" school. That's old thinking.
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Under Sean Lewis, San Diego State has flipped the script. They aren't just sitting back and winning 17-10 anymore. They want to run 80 plays a game. They want to exhaust your linebackers. In the 2025 game, they had two different running backs—Byron Cardwell Jr. and Lucky Sutton—go over 100 yards.
CSU, meanwhile, has struggled with identity. One week they’re Air Raid, the next they’re trying to establish the run because their pass protection is crumbling. In the 2025 game, they tried to be physical but ended up averaging only 2.5 yards per rush if you take out the garbage time. You can’t win in the Mountain West—or the Pac-12—playing like that.
The "New" Mountain West and the Pac-12 Shift
We are currently in a bizarre transition period. As of 2026, the landscape of Western football is unrecognizable.
San Diego State and Colorado State are both packing their bags for the Pac-12. This adds a massive layer of weight to their future games. It’s no longer just about a conference trophy; it’s about recruiting territory in Southern California and the talent hotbeds of Colorado.
Recruiting Wars
Sean Lewis just signed what many are calling the first "Pac-12 caliber" class for the Aztecs. He’s keeping local "hometown heroes" like Carson Diehl at home. If San Diego State can lock down the local talent, they become a powerhouse.
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Colorado State is currently in a scramble. With a new coaching staff and a move to a bigger stage, they have to prove to recruits that they won't be the doormat of the new Pac-12. The 2025 loss to SDSU was a recruiting nightmare because it showed a massive gap in athleticism on the field.
Tactical Breakdown: Why SDSU Won the Last One
If you re-watch the tape of the last Colorado State vs San Diego State football game, look at the third down conversions.
The Aztecs were 8-of-14. The Rams were 4-of-15.
That’s the game right there. SDSU kept the chains moving, which kept their defense fresh. Colorado State’s defense was on the field for nearly 35 minutes. By the fourth quarter, Cardwell Jr. was running through arm tackles like they weren't there.
- Tempo: SDSU used "AztecFAST" to prevent CSU from subbing defensive linemen.
- Pressure: The Aztecs recorded four sacks (Trey White and Niles King had two each).
- Efficiency: Denegal completed 81% of his passes. You aren't beating anyone when the opposing QB is that accurate.
What’s Next for Both Programs?
San Diego State is riding high. They finished 2025 with a 9-4 record and a trip to the New Mexico Bowl. Sean Lewis was even a semifinalist for the George Munger Coach of the Year. They have the "proof of concept" now.
Colorado State is in "Reset Mode." They have a new stadium, a new conference coming up, and a desperate need for a coach who can actually win the big games. They need to find a way to beat the Aztecs, or San Diego will continue to own the recruiting trail in the West.
Actionable Insights for Fans and Bettors
- Watch the Trenches: In this series, the team that rushes for more than 150 yards has won 80% of the time over the last decade.
- Snapdragon Advantage: CSU has historically struggled in San Diego, winning only 8 times in 20 tries.
- The "New Coach" Factor: Keep a close eye on CSU’s transfer portal activity this spring. They’ll likely lose some Norvell loyalists but will need to aggressively target defensive depth to compete with SDSU's tempo.
- Schedule Check: As the new Pac-12 schedule rolls out for 2026, look for this game to be moved to a late-season slot. The stakes are getting too high for an October "opener."
The rivalry is changing. It's not the scrappy Mountain West battle it used to be. It’s a high-stakes, big-money preview of what’s to come in the new Pac-12. If the Rams don't figure out their defensive identity soon, the Aztecs are going to keep running them off the field.