ARLINGTON, Texas — Within seconds of the final whistle Sunday night, a cart drove past the door of the Dallas Cowboys locker room. It carried Eagles owner Jeffrey Lurie and general manager Howie Roseman. Lurie looked grim; Roseman, stunned. Thousand-yard-stare stunned.

They had seen their future, and it was bleak.

Things had changed quickly.

On Friday afternoon, the Cowboys felt like a team on the brink of collapse. They’d lost three straight games and had fallen into a first-place tie with the 3-3 Eagles. Eight of the Cowboys’ starters were hurt. The Metroplex was calling for the head coach’s head.

But by midnight Sunday, the Cowboys looked like a boulder on a mountaintop poised to rumble down, smashing everything in its path. They looked like a mini-dynasty in the making; a mini-dynasty perhaps already made.

Dak Prescott had outplayed Carson Wentz, again. Jason Garrett had outcoached Doug Pederson, again. The Eagles had tailored their defense to corral the Cowboys’ playmakers, Amari Cooper and Ezekiel Elliott, but Elliott and Cooper combined for 253 yards and had outclassed the Eagles.

Again.

The Cowboys have become, by every measure, the best team in the NFC East. That isn’t likely to change any time soon. The Eagles’ 2017 Super Bowl season has proved to be an outlier, not “The New Normal” (that wouldn’t be the last prediction Doug Pederson got wrong).

Given the documented arrogance of “America’s Team,” as the Cowboys call themselves, this is not to be to be wished upon any division. But it is a real possibility — indeed, a probability — and it is upon us, so it must be faced, no matter how dismaying.

Garrett now has beaten Pederson four times in a row, by an aggregate score of 99-53. Garrett also has won two of the last three NFC East titles, and he regained first place after Sunday night’s 37-10 laugher.

His team, now 4-3, has a bye this week. It then resumes its schedule at the Giants; so, 5-3.

The Eagles, now 3-4, can watch that Monday night game from home, since they’ll have the bye in Week 10, but only after traveling to the 5-1 Bills this weekend, then hosting the Chicago Bears.

So, with seven injured starters — DeSean Jackson, Jason Peters, Nigel Bradham, Ronald Darby, Avonte Maddox, Darren Sproles, and Tim Jernigan — 3-5 is a lot more likely than 4-4 going into Week 9.

With a win Sunday night the Eagles had a chance to avert all of this. They could have put Jerry Jones in a vexing position: Either fire Garrett on Monday, or spend two weeks defending his decision to retain him. Garrett — in nine seasons of leading the team that practices at the end of a street called the Avenue of Champions — is 2-3 in the playoffs.

Might that change, too? It could happen. The Cowboys lost to the Saints and Packers, but those teams are both 6-1, and they played the Saints on the road, and the Packers employ Aaron Rodgers, the best quarterback ever. They then lost to the Jets, but did so without their two starting tackles, without two starting cornerbacks, and without two starting receivers (Cooper left after the first series). Five of those players returned Sunday night. All played well. DeMarcus Lawrence, who recorded his first sack in 10 games against the Eagles, was inspired.

“It’s major motivation,” said Lawrence. “Your guy is limping around and hurting, but he still comes out and battles with you?”

That’s a sign that players want to keep their coach around. A couple of playoff wins and Garrett, a lame duck in 2019, will earn an extension. None of the players who played hurt Sunday night got worse, and linebacker Leighton Vander Esch’s stinger isn’t expected to keep him sidelined when the Cowboys resume their schedule in two weeks.

They are getting healthier by the hour. They’re 36-19 since they drafted Elliott and Dak Prescott, whose 102.6 passer rating this season ranks sixth among regular starters, and whose 303.3 passing yards per game is his best by more than 20 percent.

Considering the abysmal state of the Giants and Redskins, the NFC East is a two-team race, which won’t change anytime soon. Love them or, more likely, hate them, the Cowboys are the better of those two teams, and they’re getting better all the time.

And Lurie and Roseman know it.