They received an email congratulating their team on winning the Discover BCS National Championship that hadn't yet been played.
The note came from Amazon.com, the world's largest online retailer.
"Dear Amazon.com Customer," the email that was sent to Irish fans read. "Congratulations to the Notre Dame Fighting Irish, NCAA National Football Champions. Customers who have shown an interest in the Notre Dame Fighting Irish might like to see NCAA championship merchandise and additional team fan gear."
The same note, substituting in Alabama, was sent to those whom the website had identified as Crimson Tide fans, presumably because of their past ordering profiles.
Later in the day, Amazon sent out an apology.
"Well, this is really embarrassing....we completely fumbled our congratulation (sic) email for tonight's game," the apology said. "We admit that we can't tell the future. We congratulate Alabama and Notre Dame for making it to the NCAA Football National Championship. We hope you enjoy the game."
A call placed to Amazon was not immediately returned.
Perhaps the most embarrassing championship mistake came from Macy's in 2011. The department store ran an ad in the Miami Herald selling Miami Heat championship gear. On the same page was an article with a story mentioning that the Heat lost to the Dallas Mavericks in six games.