It was a run that altered the molecular structure of everything in its path. As the burgundy blur sped by, linemen became mere spectators. Potential pass-targets became downfield blockers. Nervous fans suddenly became screaming bundles of delirium. And the shouts from the Washington Redskins’ sideline, the ones Robert Griffin III heard as he sprinted by, morphed from “Slide! Slide! Slide!” to “Go! Go! Go!”

By the time Griffin finished outrunning the entire Minnesota Vikings’ defense, crossed the goal line and leaped into the FedEx Field stands for a few awkward moments, he had also altered the trajectory of the game and quite possibly the Redskins’ season.

Griffin’s electrifying 76-yard touchdown run late in the fourth quarter Sunday — the longest by a quarterback in franchise history — provided the final cushion in the Redskins’ 38-26 victory and produced what may have been the rookie quarterback’s signature moment of this season.

“I just took off running,” Griffin said, “and the rest is history. I got to enjoy the moment a little bit. It was pretty fun to hear the crowd and see my teammates on the sidelines celebrating as I ran for the touchdown.”

As the Redskins huddled for the third-and-six play from their own 24, with 2 minutes 56 seconds left in the game and the Redskins’ lead — once a comfortable 19 points — down to just five, several players voiced the prevailing thought: Someone needs to make a play.

The play call from offensive coordinator Kyle Shanahan was a fairly simple drop-back pass play from the shotgun formation. Wide receiver Josh Morgan was split out to the left. Two more wideouts were on the right, joined by tight end Fred Davis, who went in motion prior to the snap. Joining Griffin in the backfield was running back Evan Royster.

Although the Vikings had rarely blitzed all afternoon, Griffin could see a pair of linebackers creeping toward the line, ready to pounce. If the Vikings sent six pass-rushers, they would almost certainly be in man-to-man coverage in the secondary.

“I saw the double ‘A’-gap blitz,” Griffin said. “And I was thinking I was either going to throw ‘hot,’ or if they miss this blitz — don’t hit it the right way — then I’m going to run for the first [down].”

Indeed, once the Vikings’ blitz failed to reach Griffin immediately — with Royster adeptly picking up middle linebacker Jasper Brinkley — Griffin tucked the ball and ran so quickly, it was unclear at first whether the play was a designed run or a pass.

The only Vikings defender to have any sort of shot at tackling Griffin near the line of scrimmage was linebacker Chad Greenway, who dove at Griffin’s ankles as he went by but came up empty.

“I wasn’t where I was supposed to be,” Greenway said. “I just tried to come back and make [the tackle]. I didn’t have much of a chance at all.”

As Griffin took off towards the Redskins’ sideline, teammates and coaches were yelling at him to slide — an acknowledgment of both the concussion Griffin suffered the week before on a similar run toward the sideline, and of the need to keep the clock running by staying in bounds.

“But he had the awareness to bounce it outside and take it the distance,” said linebacker Perry Riley, one of those yelling “Slide!” on the Redskins’ sideline. “Once I saw him bounce it up the sideline, and the receiver [Morgan] had a pretty good seal on the corner, I said, ‘Oh, he might take it all the way.’ And the whole sideline went from yelling ‘Slide’ to ‘Go! Go!’ ”

Once Griffin got around the corner? “You’re watching a track meet,” said wide receiver Santana Moss. “And he ain’t coming in seventh.”

Harrison Smith, the Vikings’ free safety, had a good angle at Griffin near the sideline, but perhaps underestimated Griffin’s speed, because by the time Smith got into position to make a tackle, all he could do was dive at Griffin’s feet.

All that was left was the footrace between Griffin, with a five-yard lead, and Vikings backup safety Jamarca Sanford. And it was no contest, with Griffin — the 2008 Big 12 conference champion in the men’s 400-meter hurdles as a freshman at Baylor — toying with Sanford for the last 20 yards or so.

“That dude is special,” Redskins fullback Darrel Young said of Griffin. “To look back at a DB the whole way? Man, he’s fast.”

For months, the Redskins have watched Griffin get to the outside on similar plays in practice, only to pull up and jog back to the huddle. They knew of his track prowess — though they jokingly told him they didn’t believe any of it — and always suspected there would come a time in a real game when he got to the outside and kept going. This was that time.

“I’d never seen him open up because in practice, he’d always turn around and come back,” Young said. “But today he opened up and I said, ‘Wow, so that’s what you can do.’ I heard about it. But to actually see it today — what was it, 76 yards? In the NFL, that’s a big deal, man, because . . . everyone’s fast in this league.”

Put a stopwatch to the final 40 yards of his run — with a full head of steam, to be sure, but also weighted down by his pads and his own choice to look back at Sanford several times — and it comes in at 4.08 seconds, just a few shades under the official 4.41 he ran at the NFL combine.

“I got to prove to those guys that I still have that track speed that they’ve been . . . saying I don’t have,” Griffin said with a huge grin. “I was able to break a long one. It always feels good when you can do that.”

Mike Jones contributed to this report.