EAST RUTHERFORD, N.J. — In a parallel universe, one where the opposing quarterback is someone other than Eli Manning, and where the Washington Redskins’ secondary is capable of protecting a lead late in the game, Robert Griffin III would be waking up Monday morning with a singularly satisfying feeling, having vanquished the New York Giants at MetLife Stadium with a late fourth-quarter dagger of a drive.

All the ingredients were there for a second straight thrilling win, capped by another iconic moment for the rookie quarterback. The go-ahead drive authored by Griffin on Sunday afternoon featured a converted fourth and 10 on a freelanced play deep in the Redskins’ territory, a 24-yard scramble on the first play after the two-minute warning and, finally, a 30-yard feather pillow of a touchdown throw to Santana Moss for the go-ahead score.

At that point, the heavy lifting for Griffin should have been over, another tale in the growing legend of RGIII now complete.

Instead, after Manning answered with an unfathomable 77-yard touchdown strike against the Redskins’ porous secondary, and after the Redskins’ final chance ended with a fumble by Moss, Griffin and the Redskins were stuck with a 27-23 loss that still had not sunk in a half-hour after the final seconds had ticked off.

“Right now,” Griffin said, “it’s kind of hard to know what to think.”

In the other, victorious locker room, the Giants knew exactly what to think: They had just witnessed something unlike anything else they have encountered.

“That guy is flat-out unbelievable, man,” Giants defensive end Osi Umenyiora said of Griffin. “I’m not gonna lie. That’s the best quarterback we’ve played this year.”

Griffin “takes away from your enthusiasm for the game a little bit,” Giants defensive end Justin Tuck said. “. . . I’m really mad at the football gods for putting him in the NFC East.”

Griffin’s go-ahead drive in the fourth quarter came immediately after what may have been his worst stretch of play as a professional. The three preceding possessions had resulted in a Griffin interception, a Griffin fumble recovered by the Giants and a disappointing field goal after a three-and-out following a Redskins interception deep in Giants territory.

Three plays into the drive, Griffin faced a fourth and 10 at his own 23, with 2 minutes 17 seconds to play. Flushed from the pocket, Griffin scrambled toward the left sideline, juked out of the way of defensive end Jason Pierre-Paul and found tight end Logan Paulsen over the middle for a 19-yard gain.

“It’s the purest form of football,” Paulsen said. “You’re in your backyard, and someone says ‘get open,’ and that’s what happened. . . . He saw me and made a perfect throw.”

After the two-minute warning, Griffin dropped back to pass again, was flushed toward the right sideline, saw an opening and ran for 24 yards.

“We feel like we can do anything we want, with the ball in his hands,” Moss said. “When you have a guy that gives you an opportunity every time, even when its hard, that’s a blessing. Not many quarterbacks can do that.”

Two plays later came the 30-yard touchdown pass, a perfectly thrown ball over Moss’s shoulder, hitting him in stride. Prone on the turf, Griffin grabbed his helmet in disbelief, sat up and briefly struck the “Griffining” pose — arms extended in victory — before he was engulfed by teammates.

“I saw the safety break the other way,” Griffin said, “and I’ve got Santana Moss one-on-one against a rookie. . . . You have to take advantage of that.”

In its own way, the throw was nearly as breathtaking as the 76-yard touchdown run Griffin broke off to clinch the Redskins’ win against Minnesota the week before.

“That moment is special, man,” fullback Darrel Young said. “He put us in position where we could win. If you play Madden [the NFL video game], you can’t do that in Madden. Quarterbacks can’t make that throw in Madden. It’s not realistic. There’s no one in the world who could have taught him that, what he did today.”

And that is what made Sunday’s loss so difficult for the Redskins. When a rookie quarterback walks into the home stadium of the defending Super Bowl champs and authors a moment such as that, all anyone wants to do is finish the job for him.

“He’s such a good guy, such a good teammate, such a good leader,” Paulsen said. “So, yeah . . . you want to be able to be there for him and make those plays and make things happen for him, because he is [always] there for you.”