GREEN BAY – Tramon Williams settled into his crouch, ready for the first movement Larry Fitzgerald made. As the All-Pro Cardinals receiver started off the line of scrimmage, Williams turned his hips, got close to Fitzgerald and they each began a physical assault on one another.

There was no help for Williams. It was only the second play of the game, but he had to win.

He sandwiched Fitzgerald between his body and the sideline; man coverage perfectly executed. The ball came, but it was too tight a window. Incomplete.

Later in  Green Bay's 31-17 victory over Arizona, Cardinals corner Jamell Fleming found himself alone against Packers receiver James Jones.

The Cardinals corner worked himself between Jones and the ball, forcing Jones between him and the sideline. Aaron Rodgers threw it Jones' way, to a tight window. Jones went up over Fleming's back and flailing arms and coaxed the ball into his hands. Touchdown.

Competition.

It's what those matchups are called in the Packers locker room. Quarterbacks and wide receivers love it when they see the man across from them on an island, like Jones on Fleming.

"When you see man-to-man with no help over the top and you've got a certain play call on or the quarterback checks to a certain play, your eyes light up and it's time to go," Jones said. "That's when it gets real competitive and you don't want to lose no one-on-one matchup."

It goes both ways, however. Williams and his fellow defensive backs cherish the opportunity just as much.

"You know what, you definitely got to light up because the ball is going to come when a quarterback sees you're one man high," Packers corner Casey Hayward said. "The ball's going to come. You've got to be ready and be in the right position."

Two other important man-to-man battles had an impact on the game as well: Randall Cobb beat Cardinals corner William Gay for a score on a corner route while Hayward was beaten by Andre Roberts on a deep post, which set up the Cardinals only score of the first half.

Who wins these competitions can often determine which team wins the game. Forget the game planning, forget the smart defensive calls. The fate of 22 men on the field can come down, quite simply, to only two.

"It's competition," said Packers safety Jeron McMillian.

He smiled.

"If he really thinks he's going to beat me, I'm not going to allow him to beat me."

What does that mean, though? "Competition." Players compete on a play by play basis. What is it about man-to-man coverage that creates a different feel?

Packers safety Morgan Burnett broke it down: "Mentally, you're looking forward to it. It's why you play football. You're playing in the NFL which is the highest level of all football competition and that's what you look forward to and that's what you dream about. So you go in mentally ready, you want to compete and do the best that you can do to help your team out."

And physically?

"You want to trust your techniques that your coach trains you all through training camp and all through practice," Burnett said. "You trust and rely on your techniques to put you in a good situation. As long as you're competing out there, you never can go wrong."

Then, there is the attitude.

A man on an island can have no fear of what comes his way.

"Give him your all," McMillian said. "Let him know that whoever you are, that's cool, but just know today, it's really not going to matter. We're going to play our defense as hard as we can and if it's me and you, just know I'm going to be a little more physical, I'm going to do a little bit more so they won't throw you the ball."

If a defensive back can win that competition, it has a trickle down effect. Suddenly, Packers defensive coordinator Dom Capers has the ability to tray different things to create mismatches in the pass rush, or help out other players who are struggling with their duties.

"It helps the play calling, I think," Williams said. "When you can go out there and a coach sees that you can kind of handle a guy, for the most part, one-on-one, he can go to different things schematically and help out the defense."

As a receiver, Jones said he can see such things in film study, and he can feel it during the game. He singled out St. Louis Rams cornerback Cortland Finnegan, who Jones went up against three weeks ago, as being a tremendously competitive, prideful defensive back. Jones allowed that while every defensive back in the NFL competes, there is a difference in how they do so. And that difference can be the margin between a touchdown and an incompletion.

"At the end of the day, all technique, everything that you've learned – I don't want to say it necessarily goes out the window – but in your head you know it's man to man," Jones said. "I think that's what they mean by it's 'competition'. It's man to man. I have nobody helping me over the top, it's just me and this guy. It's 'Who's going to win? Either he's going to beat me or I'm going to guard him.' When you get into man on man coverages like that, that's all it is – competition. When you start getting into zone coverages and all that stuff you're just playing the zone and it's really not competition."

Competition.

It's amazing, really, how one act between two men can decide so much.

"When you've got a man one-on-one, you know if he beats you he beats the difference," Jones said. "It's a different urgency of competition and you don't want to lose. It's the same as a receiver when you see man-to-man, you want to win at all costs. It's him versus you."