PHILADELPHIA — In an unexpected defensive tussle, the depleted Dallas Cowboys delivered the knockout punch.
Tony Romo threw for 317 yards and one touchdown, a banged-up Dallas defense shut down Chip Kelly’s prolific offense, and the Cowboys overcame a sluggish start to beat the Philadelphia Eagles, 17-3, on Sunday to take sole possession of first place in the NFC East.
At least there won’t be a quarterback controversy in Philadelphia after this one: Nick Foles was awful before leaving with a head injury.
‘‘Obviously, our defense was outstanding,’’ Cowboys coach Jason Garrett said. ‘‘That offense challenges you in so many ways. They have a really good scheme. Our defense played sound, played together. They were physical and our tackling was outstanding.’’
Two teams that averaged a combined 58.2 points per game and allowed a combined 55.2 points totaled 13 punts in a first half that ended with Dallas leading, 3-0. It was more about two inept offenses than two dominant defenses.
A Cowboys defensive line missing three of its projected starters pressured and harassed Foles until putting him out on the final play of the third quarter. With Michael Vick inactive because of a hamstring injury, Matt Barkley made his NFL debut and threw three interceptions in the fourth quarter.
The Eagles (3-4) have lost a franchise-worst nine straight games at home. Their last win at Lincoln Financial Field was over the New York Giants on Sept. 30, 2012.
Dallas (4-3) played without four-time All-Pro defensive end DeMarcus Ware, who missed the first game in his nine-year career because of a quadriceps injury. Anthony Spencer, the end opposite Ware, is out for the season after knee surgery. Four-time Pro Bowl tackle Jay Ratliff was released during the week after failing a physical.
George Selvie had 1½ sacks and combined with Jarius Wynn on the hit that forced Foles out of the game. Wynn was signed last Tuesday after being released by San Diego.
‘‘It’s a testament to how hard and committed these guys are to practicing,’’ Romo said. ‘‘It’s neat for them to have a game like this. They would’ve won it by themselves.’’
Foles, coming off an impressive performance at Tampa Bay last week that earned him NFC Player of the Week honors, had his worst game since his first career start at Washington last November. He finished 11 of 29 for 80 yards and was sacked three times.
‘‘All of us on offense, our decision-making wasn’t very good,’’ Kelly said. ‘‘It was all of us on offense. It’s not just one guy.’’
Kelly is hopeful Vick will return this week. There was no word on the extent of Foles’s injury.