To hear some folks talk, Southern Cal had already wrapped up a spot in the BCS National Championship Game before Thursday.

By beating Ohio State, 35-3, it was appropriate that Pete Carroll and his bunch go ahead and book a nice hotel with a South Beach view, then simply fire away at the fish-in-a-barrel known as the Pac-10.

One of those fish turned out to be a Beaver, however — one that took a nice size chunk out of the Trojans’ tush.

So “unbeatable” SC now has a mystifying loss to a team that fell by 8 to Stanford and 31 to Penn State. Oregon State 27, Southern Cal 21 means the club a few talking heads had dubbed head and shoulders above the rest of the 2008 class won’t even get to graduate with honors.

The Trojans might win the rest of their regular season games and claim the Pac-10 title, but their championship hopes are gone. There are quality losses and bad ones, and what happened Thursday in Corvallis was a killer.

It seems as though something like this happens every season.

We look at a team like SC come out smoking — as it did this year — and automatically assume it has no flaws, no weaknesses and no chance to stumble.

Then when it does, we move on to the next greatest team in the history of the world.

That would be the Oklahoma Sooners, who have hung more than a half hundred points on each of their three previous opponents. All they have to do to move to No. 1 with a bullet is take care of No. 24 TCU tonight in Norman.

Do that, and next week we’ll hear about how Bob Stoops has put together his finest 11 ever, one that will steamroll the Big 12 and enter the title game in Miami with a sparkling 13-0 record.

And that chatter will continue until and unless a team like Texas decides it’d rather go ahead and play the game instead of simply forfeit it. Heck, the Longhorns might even win, making the Sooners yesterday’s news.

In the meantime SC will tumble in the poll, maybe even falling out of the Top 10. That’ll open the door for Oklahoma’s rise to the head of the pack and give Georgia — the preseason No. 1 — a chance to actually move up in the rankings for the first time this year.

But I’m not going to pencil in the Sooners and the Bulldogs for a play date in Miami in January, just as I refused to hop on the SC bandwagon with just a third of the regular season in the books.

The old adage in the NFL is that on any given Sunday even the worst team in the league can defeat the best.

In college football — a sport played by kids driven as much by emotion as talent — unlikely outcomes are even more likely.

That’s why it’s one of the most enjoyable sports on the planet, as well as one of the most unpredictable.