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.
Washington answered back four minutes later when Robert Griffin III hit Santana Moss for a 26-yard touchdown.
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.
Martellus Bennett has four catches for 62 yards for New York. Hakeem Nicks has five catches for 53 yards and Victor Cruz has four catches for 46 yards.
Chase Blackburn has five total tackles to lead the Giants' defense. Stevie Brown and Chris Canty each have four. Justin Tuck has a sack.