ARLINGTON, Texas — The Giants planted a Big Blue tombstone in the center of Jerry Jones’ crown jewel of a stadium: R.I.P. 2010 Dallas Cowboys.

First they buried Tony Romo, then they buried the Cowboys.

They soared to the top of the NFC East and established themselves as the best the entire NFC has to offer and take a four-game winning streak into the bye week.

They sent a message to Rex Ryan along the lines of “Move over, big boy, we’re still here and we’re not surrendering the town to you and your Jets anytime soon.”

They ushered in the beginning of the end of the Wade Phillips Era and left Cowboys fans doubting that Romo will ever win a Super Bowl.

They rendered obsolete Jones’ grand ambition of hosting the Texas Super Bowl.

Bully for the 5-2 Giants, 41-35 winners last night in a game that was close at the end because Eli Manning threw away a touchdown instead of running the ball on third down and Clint Sintim had to recover a last-gasp onside kick.

They unleashed a killer instinct that would have brought a sinister smile to Lawrence Taylor’s face, that forced a staggering 1-5 band of underachieving desperadoes to crack at the first hint of crisis.

They showed up as the meaner, tougher, smarter, prouder, better-coached team and gleefully kicked this Team They Love To Hate while they are down . . . at least for 57 minutes.

The NFL has bent over backwar ds trying to protect its quarterbacks, long before last week’s crackdown on helmet-to- helmet hits. But no quarterback is safe from the New York Football Giants.

Here came Michael Boley, racing in untouched from Romo’s left side, planting the Cowboys quarterback into the turf at the end of a 14-yard completion to Miles Austin with 12:07 left in the second quarter, and there went Romo, and the Cowboys’ season along with it.

“When he hit the ground,” Boley said, “I heard him let out a little scream.”

Romo, the fifth quarterback KO’d this season by this Big Blue Crunch Bunch, looked like Michael Spinks in his Michael Tyson fight, flat on his back, soon helped to the locker room for X-rays on his fractured left clavicle.

“Pure luck,” said Justin Tuck.

It was 10-7 for the Cowboys at the time, because the Giants were in the process of trying to give the game to poor Phillips and the ‘Boys. If it wasn’t Manning throwing a pair of deflected interceptions, first off Steve Smith’s hands and then off Hakeem Nicks’ hands (10 free points), it was Brandon Jacobs fumbling (three free points). And if it wasn’t Jacobs fumbling, it was Dez Bryant returning a 69-yard Matt Dodge punt 93 yards (seven free points).

So that 10-7 lead had swelled to 20-7 before it sunk in to the Giants — and to the Cowboys, no doubt — that Jon Kitna, the mother of all journeyman quarterbacks, was going to have to try to be Earl Morrall. Or even Kerry Collins.

Yeah, right.

Ahmad Bradshaw began gashing the Cowboys, and when Manning wasn’t finding Smith for a touchdown, he was finding Nicks for six.

You could sense the Cowboys beginning to look for a reason to fold. You could see it in their body language. They had been beating themselves all season and they began beating themselves again now. Manning threw a quickie in the right flat and watched Mario Manningham zig as Cowboys defenders zagged for the 25-yard touchdown that made it 31-20.

It was quiet enough here to hold a funeral.

“I saw ’em give up early in the game, toward the end of the second quarter,” Jacobs said. “We just kept moving the ball, and I saw it in their eyes, that they didn’t really want to come out and play as hard as they played when they first came out.”

Romo stood helplessly on the sidelines, his arm in a sling, and Kitna looked the way you would expect a 38-year-old has-been to look, and boos rained down on him and the Cowboys.

Manning began spraying the ball all over the lot, to Nicks, to Smith, against a terrified Cowboys secondary that seemed to be playing in the Texas Rangers’ stadium, then Jacobs broke a tackle from Alan Ball, and another from Gerald Sensabaugh for a 30-yard touchdown. Jacobs punctuated it by dancing on the blue star inside the silver helmet insignia in the right corner of the end zone. It was 7-20 once, but 38-20 now. Before the unnecessary scare at the end.

“I was disgusted by the way the game ended,” Barry Cofield said. “Not the way you want to finish as game.”

But the way you want to finish the Cowboys, nevertheless.

Last Rodeo for the Cowboys. Ride ’em Giants.

steve.serby@nypost.com

