If you live in the NFC East you better beat the one-man band that is Robert Griffin III now, because it’s your last chance. One day soon, maybe sooner than soon, the kid will get a little more around him, erase the last of his occasional youthful misjudgments and be unstoppable. That was the message to take from the New York Giants’ 27-23 victory over the Washington Redskins: The Redskins’ rivals better enjoy it now, because there is an absolute wolf at their door.

It sounds ludicrous to call a divisional loss heartening, but that’s exactly what this was. When you put together a drive that can only be called immortal to take a lead over the defending Super Bowl champions, converting a fourth down play and finishing it with that spinning, 30-yard dragonfly of a scoring pass to Santana Moss with 1 minute 32 seconds to play, something is building.

When Eli Manning has to produce one of the more desperately glorious late-game heaves of his career, a 77-yarder on a dime to Victor Cruz with 1:13 to go, and still the kid is not beat, not dead, when he’s still out there dodging and flinging the ball to keep hope alive, you know that something is building. Something big.

There may be better NFL quarterback duels this season, but there will be none more interesting than this one, the first-ever meeting between Manning and Griffin. It was No. 10 versus No. 10, and in order to understand just how good the Redskins have a chance to be with Griffin, you have to understand just how good Manning already is. He’s the most lethal fourth-quarter quarterback of his generation, with an 8-1 record in his past nine postseason games and two Super Bowl most valuable player trophies. There are better statistical performers in the league, but there is not a better money player.

“He’s like Joe Montana now,” said Barry Cofield, a former Giant. “He’s just unbelievable. He was good when I was here. But he’s unbelievable right now. He’s got no quit in him. The team has no quit because they just have so much faith in him. And they’ve got playmakers on the edges. So if you’re not up two scores with less than a minute, you can’t rest. He made it. He did it again.”

Yet Griffin damn near stole this game. He fought Manning to a stalemate for all but the last 90 seconds. The environment didn’t bother him, and neither did the opponent. He met the Giants’ superb ball-control offense with equal ball control: There was only one punt in the entire first half, and Griffin completed 20 of 28 passes in the game, an efficiency that would be awesome, if it weren’t becoming so much a part of his week in, week out performance.

They were a study in contrasting styles. Manning’s body language was more still and observant, hands on hips, surveying, slope shouldered, undemonstrative. A stance radiating comprehension and poise, rarely surprised, almost never panicked.

Griffin was keener and sharper-edged, long-legged and cinch-waisted, pacey and opportunistic, always ready to turn a simple dive play into a 24-yard gain. Quick from huddle to line of scrimmage, crouching, rhythmic, running the offense with a crackle that was almost audible.

Much of the second half was forgettable; each guy committed a couple of what-was-he-thinking turnovers. But then came those last three minutes, an exchange that just may be the beginning of a fascinating rivalry.

The kid was behind, deep in the fourth quarter, which is supposed to be Eli’s time, not his. Except on a seemingly insurmountable fourth and 10 from his own 23-yard line, Griffin scrambled to his left, swiveled, and off one leg, as he was falling to the turf, flung that 19-yard completion to Logan Paulsen.

And while the Giants were still catching their breath, he dashed around right end, burning up the ground for 24 more yards. And then he saw Moss in single coverage and kited that beautiful touchdown pass to put the Redskins ahead again.

It should have been good enough. Against anyone but Eli Manning, it probably would have been. But the lead lasted just a few seconds. Stephen Bowen was bearing down on Manning when Cruz split the double team between Josh Wilson and Madieu Williams, and gained a step. Manning might have overthrown Cruz, or underthrown him. Instead he lofted a pass so pretty that you could practically see the laces when it dropped into Cruz’s hands.

“Great throw,” Redskins Coach Mike Shanahan said. “Double covered, right on the money. Big time throw.”

The difference between these two quarterbacks, and these two teams, was a half step and a fingertip. When the Redskins get the bile out of their throats, they will recognize that — and will also recognize that while Manning is in his prime, Griffin is just beginning. The Giants have a complete and deep roster; the Redskins are still a work in progress. The Redskins lost this one, but they are clearly the organization with the bigger growth potential.

“That’s what we’re here for, we’re competitors, he did a good job of leading them to victory today, and hopefully in the future I’ll have many more chances to do that for my team,” Griffin said.

Many, many more.

For previous columns by Sally Jenkins, visit washingtonpost.com/jenkins.