Both of Tebow's scoring throws went to Quentin Sims in the fourth quarter, rallying the Patriots to their third win in four preseason contests.
Tebow hit Sims with a 52-yarder early in the fourth quarter that gave New England a 21-20 lead.
The Giants gave up the ball deep in its own end of the field during the final seconds in a desperation attempt to move the ball into field goal range. New England took over at the New York 9-yard line and instead of kneeling down to let time run out, Tebow threw another scoring pass to Sims with just 6 seconds remaining.
Tebow completed 6-of-11 passes for 91 yards with an interception.
New York's Eli Manning played more than most starting quarterbacks do in a final exhibition game, going 6-of-9 for 74 yards and a touchdown. His 3-yard scoring pass to Hakeem Nicks in the opening period was one of just three touchdowns produced by the New York offense during a 1-3 exhibition campaign.
The Giants start their regular season in the first Sunday night game of the year on Sept. 8 at Dallas. It will be the fifth time New York has played in the new Dallas stadium and the Giants have won all of the first four. New England will play earlier that day at Buffalo.