Josh Brown kicked a 37-yard field goal with 38 seconds to play after Belichick went for a first down in his territory late, and the Giants capped their first undefeated preseason since 2006 with a 16-13 victory on Thursday night.
The Patriots coach went for it on fourth-and-1 from his 39 with less than three minutes to play and the score tied. Patriots rookie Jimmy Garoppolo threw his pass between two receivers and the Giants (5-0) ran off six plays to set up Brown's third field goal.
"I knew it was going to happen," Giants punter and holder Steve Weatherford said of Belichick's decision. "We would have done the same thing. We saw what we needed to see and it was time to get it over with. He (Belichick) was in the same position. Everyone was healthy for the most part. As much as you want to win, it's better to get out healthy."
The Patriots (2-2) started just two regulars and trotted on Tom Brady to hold on the first of Stephen Gostkowski's two field goals. Other than that, he stayed on the bench for the defending AFC East champions.
New England opens the season a week from Sunday at Miami.
There were many in New England who felt that Garoppolo was getting a chance to win the backup job from Ryan Mallett with this start. If he did, Belichick wasn't talking about it.
"I think it was a good experience for him," Belichick said. "It will help his development. He's obviously got a long way to go. He learned a lot from the week."
The Giants, who have missed the playoffs the past two seasons, play at Detroit in a Monday night game Sept. 8.
The final preseason game was left in the hands of backups for the most part. New England used regulars guard Josh Kline and safety Duron Harmon, while Giants starters played two series.
All the scoring came with reserves on the field and the Patriots were more impressive, with Garoppolo leading scoring drives of 82, 61 and 59 yards. He capped the first one with a 33-yard pass to Aaron Dobson early in the second quarter for a 7-3 lead. Gostkowski had field goals of 37 and 21, with the later giving New England a 13-10 lead late in the third quarter.
Brown, who beat out first-year kicker Brandon McManus earlier this week, tied the game in the fourth quarter with a 45-yarder. He had put New York ahead 3-0 following an interception by Zack Bowman in the second quarter. Peyton Hillis, who missed three weeks with an ankle injury, scored on a 1-yard run to put the Giants ahead 10-7 late in the half.
Bowman, who played with the Bears last season, felt it was important for the Giants to win in the preseason.
"It means a lot, it's the attitude we want to take on the field into the season," Bowman said. "You don't want to be 0-4 going into the season. But at the same time, it helps us a lot coming off last year (7-9). We want to keep this going. We want to keep this momentum going."
The Giants' new West Coast offense came into the fifth preseason game struggling, and it didn't show much in generating one first down against Patriots scrubs. Their final play summed up the preseason, despite the unbeaten record. On a third-and-2 from the Giants 28, Eli Manning hit tight end Kellen Davis for no gain.
A second-round pick out of Eastern Illinois, Garoppolo showed poise in his first start, completing 22 of 42 for 284 yards, a touchdown and an interception.
"It could have went better," Garoppolo said. "There are some things we messed up, fixable things."
Manning (1 of 4 for 0 yards), Ryan Nassib (6 of 14 for 107 yards) and Curtis Painter (3 of 5 for 32 yards) could not match those statistics combined.
"Our goal was to do some things, see what we needed to improve on and to get out healthy, and I think we did that," said Manning, who finished the preseason 20 of 41 for 188 yards, one touchdown and no interceptions.