It's difficult to say one play changed the course of a season.
But in the case of the Carolina Panthers, quarterback Cam Newton's late-game fumble in a Week 4 loss to the Atlanta Falcons seemed to do just that, sending their once-promising season spiraling downward.
On the flip side, the win galvanized the Falcons, who would go on to win seven of their next eight games en route to clinching the NFC South division title last week.
Carolina fans remember the play well.
On a third-and-2 at the Atlanta 46, the Panthers needed only to pick up a first down to seal an impressive road win against the then unbeaten Falcons.
And Newton got it, but then misfortune struck.
After Newton initially crossed the first down marker, the ball was jarred loose and bounced backward. The Panthers recovered but they no longer had the first down and coach Ron Rivera decided to punt on fourth-and-1.
Rivera's strategy looked like it might work. The Panthers pinned the Falcons down at their own 1 with 59 seconds left and no timeouts.
But quarterback Matt Ryan completed a long pass to Roddy White and the Falcons quickly moved into field goal range and Matt Bryant kicked the game-winner with 5 seconds left for an improbable victory.
Final score: Falcons 30, Panthers 28.
An exuberant Ryan left cursing at the Panthers sideline after the chippy game, telling them in no uncertain terms to get off their field.
The Panthers were devastated. Instead of being a game behind the Falcons, they were 1-3 and three games back in the NFC South.
Rivera called the loss "gut wrenching."
The Panthers would lose their next four games — even though they led in the fourth quarter in three of those games.
"At some point you should be able to snap out, but it did carry over," Rivera said. "And it hit Cam as hard as anybody because it was very personal for him being from Atlanta. He wants to play well there. But yeah, it did carry over for the next week or two. I remember the Wednesday practice the following week was just brutal."
Losing close games has become the norm in Carolina. In two seasons under Rivera the Panthers are 1-12 in games decided by seven points or less.
Falcons tight end Tony Gonzalez can relate to Carolina's frustration.
"I've been on a team like that in Kansas City where we won two games but every game was three or four points as far as the loss goes," Gonzalez said. "I don't know what it is, but good teams find a way to win."
The Falcons certainly have.
They avenged their only loss last week against New Orleans, and now they're looking to clinch home-field advantage. Next up are the Panthers and there's a pretty good chance emotions will be riding high when the Falcons show up.
The Panthers have grown a little tired of Ryan, who has defeated them in each of his last six starts. Also, Carolina's players were not happy with Ryan's celebration after the win, with some calling it "disrespectful" after TV cameras caught the quarterback cursing at the Panthers sideline about getting off their field.
Panthers defensive end Greg Hardy said the rematch is about "payback" and "punishment."
"We owe them something and it is coming," Hardy said. "I'm trying to mess with their whole playoff experience. I want them to go home sick in the stomach and mad about life, a couple of depression issues, all types of things. It's going to be a long day from my point of view. I'm coming."
Hardy even claimed the Panthers (3-9) are "a better team" than the Falcons.
The Falcons (11-1) might want to grab Hardy for a moment and simply point him in the direction of the scoreboard — or maybe the standings.
White said Ryan is a "fiery guy" and nobody in the Falcons locker room has a problem with what he said after the last game, although he certainly didn't expect anyone to catch him on camera.
"He wants to win. Just speaking in general, I didn't have a problem with what he said. It is our field. So get off it! Get lost!" White said with a laugh. "It's that simple.
"Those guys, they've been close to beating us the last couple of years. They felt like they should have won some of the games and they felt like they're a better football team than us, so they've got a chip on their shoulder and we felt like we're a better football team than them. So the war of words always comes out."
Despite Carolina's record, the Falcons know they're probably going to be in for a game.
In the first game, Carolina dominated most of the time and sacked Ryan seven times — Georgia native Charles Johnson was credited with 3½ of them. Also, Newton threw for 215 yards and two touchdowns and ran for 86 yards and another score.
Of course, it's the one fumble that still stands out.
"To lose a game like that is always hard," Newton said. "Me personally, I felt I could have did something that could have had a part in us winning. I think that's the hard part.
"Secondly, it's a rivalry game. The Panthers and the Falcons have always had a bad taste in each other's mouth when facing each other. With me being from Atlanta, it's even a more added dimension to the game. I want to win this game."
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