The New Orleans Saints entered as clear underdogs in their "Sunday Night Football" matchup against the Dallas Cowboys.

"No Drew Brees? How do the Saints think they can beat the undefeated Cowboys?"

The answer was simple: their harsh and impactful defense. Despite the Cowboys scoring the only touchdown of the game, New Orleans' defense imposed their will on Dallas, especially when it mattered most on one final drive, and left the Mercedes Benz SuperDome with the 12-10 win.

The Saints defense under coordinator Dennis Allen accomplished two things that gave the Cowboys fits. They shut down both Ezekiel Elliott and Amari Cooper, two of Dallas' best offensive players.

Despite scoring a one-yard touchdown, Elliott rushed for just 36 yards on 18 carries. That's right. Ezekiel Elliott was fed to the Saints defense, and managed just 2.0 yards per carry on Sunday. Dallas' braintrust continued attempting to feed him, often on first down. It simply never worked.

As for Cooper, cornerback Marshon Lattimore shadowed him for the entire game, and held him to just five catches for 48 yards. There's talk about Lattimore stepping up in more important contests, and that heightened version of the OSU corner certainly showed up Sunday.

With Elliott and Cooper both factored out of the game, the Cowboys got flashbacks of their 2017 campaign, during which Elliott was suspended and Cooper was a member of the Oakland Raiders.

The success of the Cowboys was placed on the shoulders of quarterback Dak Prescott. While the fourth-year signal caller completed 66.7% of his passes, he was limited to 223 yards, zero touchdowns, and one interception. The Saints knew they could win with Elliott and Cooper out of the equation, while making Prescott throw the ball. Despite a 3-0 record entering this contest, he was unable to prove to the masses that anything has changed with regard to his ability to carry an offense.

Credit the New Orleans defensive unit once again.

If you need any evidence, look at the second-to-last pass of the game, in which Prescott elected to throw to Cooper in quadruple coverage.

The Saints offense struggled with Teddy Bridgewater under center, and Dallas' defensive effort was also quite sterling. Yet New Orleans proved that even when the offense is in flux, the defense will step up and help lead the team to wins, right up until Drew Brees returns from injury.