KNOXVILLE, Tenn. — Their mood was a shell-shocked wake, the misery that comes from watching a brilliant opportunity slip on past.

No. 20 South Carolina knew what it was playing for Saturday at Tennessee. It knew what it should have lost in a 23-21 defeat to the unranked Volunteers. The defeat could have meant devastation.

Except, before Gamecocks linebacker T.J. Hollomon met with the media underneath Neyland Stadium, he slipped a look at scores from around the league.

“We knew we blew it,” Hollomon said. “I just saw on ESPN that Florida and Georgia lost, so we just have to go out next week with a good spirit and just do our thing against Missouri.”

You thought the Gamecocks’ loss in Knoxville was shocking? Try Florida losing to Missouri and its backup quarterback. More unbelievable, Georgia lost at Vanderbilt.

It was a shakeup Saturday in college football, the kind of weekend that usually happens just once every fall. In all, five teams in The Associated Press top 10 lost, the first time that happened since 2007. Nowhere did the shakeup have more of an effect than the SEC East race.

Want an example? Neither Florida nor Georgia is ranked in this week’s polls. No. 5 Missouri, one of two undefeated teams left in the SEC along with top-ranked Alabama, now has a two-game lead in the division.

USC’s chances of winning a divisional title should have died in Knoxville, Tenn. They didn’t, thanks to help from their fiercest rivals. Now, the path to Atlanta and the SEC championship game will be hard, but it can be navigated with three clearly defined steps.

The Gamecocks almost certainly have to win the rest of their conference games. They will be favored in every game except next week’s trip to Missouri. Next week’s game is also the final time USC will play on the road this season.

Georgia has to lose once more. November games against Florida and No. 11 Auburn are both possibilities. Missouri would win a three-way tie between the Gamecocks and Bulldogs because of a better divisional record.

Missouri must lose two games. In this scenario, one would be against the Gamecocks. The best chance for a second Tigers loss comes in their final two games — Nov. 23 at Mississippi, and Nov. 30 against Texas A&M.

The above three-step scenario would put USC and Missouri in a two-team tie for the SEC East crown. The Gamecocks would win the head-to-head tiebreaker.

“I think we all know there’s a lot of ball still left for everyone,” Spurrier said. “I think it’s hard to say what’s going to happen, because Missouri hasn’t lost. Missouri has a nice lead on everybody right now. But we’ve just got to worry about playing smart, disciplined football against Missouri. That’s the only thing we need to worry about, really.”

Spurrier wasn’t thinking too much about the losses suffered Saturday by USC’s divisional rivals. He said he couldn’t sleep well Saturday night. He tried to watch Clemson’s 51-14 loss to Florida State, at least “until it got out of hand.” In his mind, Spurrier went over the plays he called, what he should have called, wondering how things could have been different.

“You always wonder, what if you had called this play or that play, or just one play here or there when you lose a game like this,” Spurrier said. “But, there is a lot of parity, probably.”

So it comes down to this. Spurrier knows his team must win Saturday at Missouri. Not simply to get over the bitterness from Rocky Top, not simply to start a new winning streak, but because the Gamecocks’ next opponent holds the key to a goal that remains attainable.

“If somebody can beat Missouri, that would be the key,” Spurrier said. “If somebody can beat Missouri.”