Colt McCoy's successful return to Texas trumped Tony Romo's dramatic return to the game.
McCoy directed Washington to Kai Forbath's 40-yard field goal in overtime and Dallas was unable to answer after Romo came back from an injury to his surgically repaired back, sending the Redskins to a 20-17 victory on Monday night that snapped the Cowboys' six-game winning streak.
McCoy, the former Texas star playing at the home of the Cowboys for the first time since his final college game in his home state, calmly drove the Redskins (3-5) to the winning points.
The Cowboys (6-2) had one last chance, but didn't get a first down. Romo's final pass on fourth down was knocked away by Bashaud Breeland.
Romo left after getting sacked by Keenan Robinson in the third quarter. He lay motionless for several minutes but returned for the final Dallas drive of regulation.
The 34-year-old Romo, who had surgery for a herniated disk last December, reached for his back after the hit and stayed flat on the ground before trainers rolled him to his side. He walked to the locker room mostly under his own power.
Coach Jason Garrett said X-rays were negative and Romo had a back contusion.
He played through a back injury against the Redskins last year, leading a winning drive that kept the Cowboys' playoff hopes alive. But he had to sit out a season-ending loss to Philadelphia that kept Dallas out of the postseason for the fourth straight year.
This time, it was McCoy getting the win in his first start in almost three years after beginning the night with a career record of 6-15.
McCoy, who was 25 of 30 for 299 yards, threw 23 yards to Pierre Garcon to get the winning drive going. On third-and-3 from midfield, he fled the pocket, pointed to Jordan Reed to run up the field and lofted a pass that Reed caught while tiptoeing inbounds.
Another 16-yarder to Reed made Forbath's job much easier.
Cowboys running back DeMarco Murray extended the record he took from Jim Brown a week ago with his eighth straight 100-yard rushing game to start the season. He had 141 yards rushing and another 80 receiving.
Brandon Weeden took over at quarterback after Romo was hurt, and his first play was a handoff to Murray for 51 yards to the Redskins 6, pushing him over 1,000 yards for the second season in a row.
The previous Dallas running back with consecutive 1,000-yard seasons was NFL career rushing leader Emmitt Smith with 11 in a row from 1991 to 2001.
McCoy put Washington up 17-10 early in the fourth quarter with a 7-yard run on a quarterback draw, slicing between three defenders across the goal line.
Weeden answered with a matching 80-yard drive capped by his 25-yard scoring pass to Jason Witten.