The Cowboys (9-5) beat their NFC East rivals for the 12th time in the last 13 meetings and solidified their hold on the NFC's first wild-card spot.
The Dallas defense held the Redskins to eight first downs and 161 total yards.
Making his third straight start, Tim Hasselbeck completed just 6-of-26 passes for 56 yards with four interceptions.
Former Titans kicker dies in car crash
UPI Sports Results for September 20, 2014