Buffalo went into their bag of tricks just before halftime during the 26-15 win at AT&T Stadium. Bills quarterback Josh Allen handed off to wide receiver Andre Roberts on a reverse at the start of the play. Roberts then flipped the ball to John Brown, who threw a 28-yard touchdown pass to running back Devin Singletary.
The score gave the Bills a 13-7 lead, which they would not surrender. It also came amid a run of 26 unanswered points.
Allen completed 19 of 24 passes for 231 yards and a score, while also rushing for a touchdown in the win. Former Cowboys wide receiver Cole Beasley had 110 yards and a touchdown for the Bills. Bills defender Ed Oliver picked up two sacks in the victory.
Cowboys quarterback Dak Prescott threw for 355 yards and two scores, but also threw an interception and lost a fumble.
"The coaches put a really good game plan together," Bills coach Sean McDermott told reporters. "With that in mind, on a short week, to be able to execute at a high level, the players did a phenomenal job."
The Cowboys took a 7-0 lead after Prescott connected with Jason Witten for an eight-yard score on the game's opening drive. Dallas and Buffalo each punted on their next two drives before the Bills tied the score in the second quarter. Allen connected with Beasley on a 25-yard touchdown pass, capping off the eight-play, 85-yard drive.
Brown then hit Singletary for the go-head score, two minutes before halftime.
Stephen Hauschka made a 41-yard field goal to give the Bills a 16-7 lead in the third quarter. Allen ran for a 15-yard score on the Bills' next drive, increasing the lead to 23-7. Hauschka hit another field goal for the Bills midway through the fourth quarter.
Prescott led the Cowboys on a five-play, 70-yard scoring drive with 4:06 remaining. The Cowboys quarterback connected with Ventell Bryant on a 15-yard touchdown pass to cap off that drive. The Bills ran out the clock after they recovered an onside kick following the Cowboys' touchdown.
"Obviously everyone is disappointed," Cowboys coach Jason Garrett said. "Unfortunately We didn't put enough to win the ballgame. Everyone puts so much into it and we didn't get the job done."