Grossman was 11-of-21 passing with a 7-yard touchdown throw to Pierre Garcon in his first start of the pre-season. Pat White was 7-of-14 passing for 96 yards and also rushed for 26 yards and a touchdown for Washington.
Keiland Williams rushed for 52 yards and a TD and the Redskins improved their pre-season record to 3-0.
Kevin Kolb -- starting at quarter for the injured EJ Manuel -- played just two series for the Bills before leaving the game with concussion-like systems. Kolb was 2-of-4 for 16 yards.
Jeff Tuel went the rest of way at quarterback for Buffalo, going 10-for-17 for 63 yards
The loss was the Bills' first of the pre-season.
Washington amassed 27 first downs to eight for the Bills.