Drew Brees completed 83 percent of his passes (34 of 41) for 392 yards and four touchdowns. New Orleans also piled up 242 yards rushing, and the team's 625 yards were a franchise record for a regular season game.
Saints running back Mark Ingram gained a career-high 145 yards rushing versus the Cowboys.
NEW ORLEANS (AP) - Sean Payton had a choice to make.
The Saints coach could elect to punt on fourth-and-5 from the Dallas 42, or he could try to get the one last first down New Orleans needed to set an NFL record.
Only two minutes remained and victory was assured, so Payton figured he couldn't deny his players a chance to make history.
He called for a run behind right guard Jahri Evans, and Pierre Thomas powered for the 5 yards the Saints needed for their 40th first down in a 49-17 demolition of the Cowboys.
The play typified how New Orleans' offense had its way with Dallas' beleaguered defense all night.
"To come in a win like this, it's fun," Saints quarterback Drew Brees said of the single-game first-down record. "It says a lot about just today. Today was extremely efficient, both in the run and the pass."
Brees completed 83 percent of his passes (34 of 41) for 392 yards and four touchdowns. New Orleans also piled up 242 yards rushing, the most since they gained 249 yards on the ground at Cincinnati in 1990.
New Orleans' 625 yards were a franchise record for a regular season game, eclipsed only by their 626 yards in a playoff win over Detroit two seasons ago.
"I thought we got into a pretty good tempo and I thought we had a pretty good plan going in," Payton said. "It's important for us to have that balance. ... The offensive line did a good job."
Dallas, by contrast, was frustrated offensively against a Saints defense that has turned around dramatically under new coordinator Rob Ryan, who was fired by the Cowboys after last season.
"You have to give them credit for outplaying us and kicking our tails real good," Cowboys tight end Jason Witten said. "Obviously, we have to play a lot better moving forward."
Here are five reasons why the Saints (7-2) cruised to the victory they needed to maintain sole possession of first place in the NFC South, and why Dallas (5-5) has dropped into a tie with Philadelphia for the NFC East lead:
PRIME-TIME SAINTS: The Saints haven't lost a night game in the Superdome for more than three seasons now, winning 12 straight home games in prime time, including a pair of playoff victories.
Dallas was the last team to beat the Saints in the dome at night on Dec. 19, 2009. Since then, and Saints have treated national television audiences to some memorable performances. Those included the night Brees broke Dan Marino's nearly three-decade-old record for yards passing in a season, and the night he broke Johnny Unitas' record for consecutive games with a TD pass.
In one stretch against Dallas, Brees completed 19 straight passes, tying personal and franchise marks.
DEFENSIVE DIFFICULTY: Dallas had to start the game without one of their top defensive linemen when tackle Jason Hatcher was ruled out with a neck injury. During the game, the Cowboys' leading tackler, linebacker Sean Lee, left with a hamstring pull. Then defensive end DeMarcus Ware re-aggravated his quadriceps injury.
The 625 total yards the Cowboys gave up was a franchise record, eclipsing a mark set just two weeks earlier, when Dallas gave up 623 yards to Detroit. The performance dropped Dallas to last in the NFL in total defense.
INGRAM'S DESIRE: Most of Mark Ingram's first three seasons have been defined by nagging injuries and unmet expectations. The former Heisman Trophy winner produced in flashes but never had a 100-yard game - until Sunday night. Ingram smashed his career high of 91 yards by gaining 145 to go with a short TD run. More impressively, he did it on only 14 carries.
"He was a man on a mission today," Brees said. "This is kind of just breaking the seal for what he's capable of."
SLOWED STARS: Dallas didn't just struggle on defense against the Saints. Star receiver Dez Bryant, covered mostly by Keenan Lewis, did not have his first and only catch - a 44-yarder - until late in the third quarter. Jason Witten was held to two catches for 27 yards. Romo was 10 of 24 for season-low 128 yards and was sacked three times.
Cowboys owner Jerry Jones called the performance of his team "embarrassing," adding, "The real issue now is what are we going to do about it?"
BETTER BLOCKING: The Saints' offensive line has been the subject of significant scrutiny this season. The Saints' running game was 26th in the league entering Week 10 and Brees had been sacked 20 times. But Brees was sacked only once by Dallas, and that same offensive line got a lot of credit from teammates for the club's success both running and passing.
Brees termed his linemen's performance "phenomenal," adding, "Every one of them deserves a game ball."