Jackson scored on the fourth play of the game, going 67 yards on an end-around.
McNabb was 15-of-25 passing for 156 yards and the touchdown pass to Jackson. Will Witherspoon, acquired by Philadelphia in a trade with the Rams last week, ran an interception back 9 yards for a touchdown and forced a fumble that resulted in a field goal by David Akers.
The Eagles (4-2) played most of the game without running back Brian Westbrook, who left the game in the first quarter with a concussion after taking a knee to the helmet by Washington linebacker London Fletcher.
Quarterback Jason Campbell was 29-of-43 passing for 284 yards and two touchdowns for the Redskins (2-5) but he threw the costly interception and was sacked six times.
Devin Thomas caught a 2-yard TD pass from Campbell, who connected with Fred Davis for a 1-yard scoring strike with 1:38 left to play. It was Davis' first NFL touchdown.