Manning completed 21-of-33 pass attempts for 330 yards with one interception for the Giants, who advance to next week's NFC title game against the San Francisco 49ers.
Manning found Hakeem Nicks on two scoring strikes -- including a 37-yard, Hail Mary pass as time expired in the first half for a 20-10 lead -- and iced the victory with a 4-yard touchdown pass to Mario Manningham in the fourth quarter.
Nicks made seven grabs for 165 yards, while Victor Cruz added five catches for 74 yards for New York, which avenged a 38-35 loss to the Packers Dec. 4 in New York.
The Giants' defense forced the Packers into three costly fumbles and an interception, which led to 10 New York points.
Green Bay's Aaron Rodgers went 26-of-46 through the air for 264 yards and a pair of touchdowns, but lost a third-quarter fumble. He also ran six times for 66 yards.