COLUMBIA, Mo. -- Connor Shaw walked wearily from the South Carolina locker room late Saturday night looking like he'd just gone 15 rounds with the heavyweight champion.

One of college football's gutsiest fighters, Shaw also wore a confident smile.

Already gimpy with a sprained knee and battling a nasty stomach virus that had him throwing up three hours before the game, Shaw came off the bench in the third quarter to bring South Carolina back from the dead in an improbable 27-24 double-overtime victory over No. 5 Missouri at Faurot Field.

"It's a relief more than anything, like a huge burden has been lifted off this entire team," Shaw said. "This is a game we had to have."

A hobbled Connor Shaw came off the bench to rally the Gamecocks and throw the SEC East up for grabs. MCT via Getty Images

It's also a game that threw the SEC's Eastern Division race into a muddled mess and further punctuated the cannibalistic nature of the league this season.

As we head into the month of November, there's exactly one unbeaten team remaining in the SEC -- No. 1 Alabama. Missouri would have made it two, but couldn't make a 17-0 lead in the fourth quarter stand up and didn't have any answers for Shaw, who finished 20-of-29 for 201 yards and three touchdowns after entering the game at the 6:46 mark of the third quarter with his team reeling.

"That's what great players do, and Connor's a great player. I hope everybody knows that," said Jadeveon Clowney, South Carolina's star defensive end. "He put this team on his back tonight."

The senior wasn't even expected to play in the game. The knee he sprained last week in the loss at Tennessee was debilitating enough, but he suffered from flu-like symptoms on Friday while throwing up most of the night and received intravenous fluids Saturday.

His parents, Lee and Dawn, were so sure he wasn't going to play that they canceled their trip to Missouri at the last minute.

"We watched (on television) and cried together," joked Lee, who coaches high school football in Georgia and has been known to drive all night to see his son play.

This is one they might remember for a long time in the Land of the Gamecocks if they go on to win the Eastern Division and make it to Atlanta.

South Carolina (6-2, 4-2 SEC) has two games remaining in the league, against Mississippi State and Florida, both at home. Missouri (7-1, 3-1 SEC) still has four conference games left. The Tigers get Tennessee at home next week, then Kentucky on the road, and after a bye week, close the regular season with a road game at Ole Miss and a home game with Texas A&M.

Florida and Georgia are also back in the mix, at least the winner of next week's game in Jacksonville. In other words, it's wide open.

"If it works out for us, we might look back and wonder, 'How in the heck did we win this one?' " said South Carolina coach Steve Spurrier, who won his first overtime game as a coach. "But these are the kind you've got to win if you're going to do something special."

And having a special player sure helps.

"Connor wasn't going to let us lose that game, plain and simple," Clowney said. "We rallied around him, and he rallied around us. A lot of people might have thought we were done after we lost last week, and I know they probably thought that after the way this game started. But this team doesn't quit. We keep fighting, and we keep leaning on each other."

Even Shaw, the Gamecocks' version of Mr. Unbreakable, wasn't sure he'd be able to play Saturday. But after the pre-game meal, he started to feel a little better and told Spurrier he could play if the Gamecocks needed him.

Dylan Thompson started the game at quarterback, and while the Gamecocks moved the ball at times, they turned it over three times in the first half. Mike Davis fumbled twice, once at the Missouri 2, and Thompson also threw an interception.

"It was Dylan's game, and that's the way we went into it," Shaw said. "But I wanted coach to know that I was good to go if they needed me."

So after the Gamecocks went nowhere on their first possession of the second half and Missouri padded its lead to 17-0, Spurrier turned to Shaw.

"He did a little bit in practice this week," Spurrier said. "I really wasn't sure (if he could play), but he assured me that he could. That's just the way Connor is. He didn't play his best last week at Tennessee, but he's always going to be there for his team."

Counting the two overtime periods, Shaw was on the field for six possessions. The Gamecocks scored points on five of those six. His 2-yard touchdown pass to Nick Jones with 42 seconds to play forced overtime.

But it was Shaw's 15-yard touchdown pass to Bruce Ellington in the first overtime that was the most improbable of all. The Tigers had scored a touchdown on their possession in overtime to take the lead, and the Gamecocks were down to their final play. Shaw had been thrown for a 6-yard loss on first down from the 9, so it was fourth-and-goal from the 15.

Shaw's eyes lit up when he realized the Tigers were in man coverage, and he threw a strike to Ellington on a corner route.

"I had no idea that would be there," Shaw said. "But it was, and I just wanted to make sure I got the ball out."

The Gamecocks then had to play a little "field-goal defense" in the second overtime after Elliott Fry put them ahead with a 40-yarder. Missouri's Andrew Baggett couldn't answer. His 24-yard attempt bounced off the left upright, setting off a wild celebration on the South Carolina sideline.

"That did not come down to just one player or one kick or one throw or one catch," said Missouri coach Gary Pinkel, whose Tigers were trying to go 8-0 for the first time since 1960. "We all could have done something different to help win that football game."

Depending on how the rest of this season plays out, it's a game that might sting for a long time for the Tigers.

Shaw, who already had overcome a separated shoulder earlier this season, might also sting for a while, at least physically.

But he'll live with it. He's used to it by now.

Or as Clowney says, "That's why he's Connor Shaw. He's the heart of this team."