The Giants kicked two field goals in the final four minutes of the second quarter. Tynes also hit a 27-yard field goal with 3:53 left in the first half.
After being down 3-0 at the end of the first quarter, Giants running back Andrew Brown rushed for a 1-yard touchdown to put the Giants up, 7-3.
Redskins kicker Kai Forbath kicked a 43-yard field goal with less than 2 minutes left in the half for his second field goal of the game.
Eli Manning is 17-of-26 for 186 yards for the Giants.
Ahmad Bradshaw is New York's leading rusher. He has 14 yards on four carries. Brown has 11 yards on three carries, including a touchdown.