The Adam Gase era is off to a crushing start.

In a game in which the defense forced four turnovers and a safety, new additions Le’Veon Bell and C.J. Mosley looked sharp and the Jets got out to a 16-point lead, they were left hanging on for dear life as the final minutes of the fourth quarter ticked down.

The Bills finally delivered the dagger, sucking the air out of MetLife Stadium on Josh Allen’s 38-yard touchdown pass to John Brown with 3:00 left to send the Jets to a devastating 17-16 loss Sunday afternoon.

Sam Darnold tried to lead a comeback drive, but it was short-lived. After getting a first down, Darnold threw four straight incompletions as the Jets went down without a real fight.

On Allen’s game-winning touchdown pass, he picked on cornerback Darryl Roberts, who was called for defensive pass interference on the play. It didn’t matter as Brown hauled in the pass and shrugged off Roberts to clear his way to the end zone for the score.

Kaare Vedvick’s two missed kicks loomed large — one a PAT and one a 45-yard field goal. The Jets claimed him on waivers last weekend after going through two other kickers in the preseason, and they still have a problem.

Mosley’s impressive Jets debut was cut short as he was declared doubtful to return early in the fourth quarter with a groin injury. The Bills immediately took advantage without him in the middle of the defense, putting together an eight-play, 85-yard drive that ended with a 3-yard touchdown run by Josh Allen. It cut the Jets’ lead to 16-10 with 10:21 left before the Bills scored the go-ahead touchdown on their very next drive.

Bell told Gase not to hold him back, in his first game since Jan. 14, 2018, and the coach obliged. Bell was involved early and often, finishing with 16 carries for 60 yards and six catches on nine targets for 32 yards and a touchdown.

But Darnold was under pressure throughout the game. His offensive line didn’t get any work together during the preseason and it showed with the Bills racking up four sacks. Darnold had multiple passes tipped down at the line of scrimmage and had to rush his throws on other occasions to avoid getting drilled.

Despite forcing four turnovers in the first half, the Jets entered halftime with just a 6-0 lead, and those points came on Mosley’s easy pick-six off a deflection. The Jets mustered just 104 yards of offense before the break, averaging 3.7 yards per play.

The Jets defense provided the points again early in the third quarter, extending its lead to 8-0. After a Lachlan Edwards punt was downed at the Bills’ 2-yard line, Frank Gore took a handoff in his own end zone and couldn’t get out, met at the goal line by Brian Poole for the safety.

Darnold finally got the offense into the end zone with 7:01 left in the third quarter. Two plays after he had a touchdown pass overturned because of an offensive pass interference — called after a booth review — Darnold found Bell for a 9-yard touchdown pass. The two connected again on the two-point conversion after Darnold scrambled and improvised, lofting one to Bell in the corner of the end zone for the 16-0 lead.

The Bills broke the Jets’ shutout with 3:48 left in the third quarter, settling for a 43-yard field goal from Steve Hauschka to make it 16-3.

Offense was optional in the first half for both teams. The Jets struggled moving the ball and the Bills struggled holding onto it. Mosley and Steve McLendon recovered fumbles while Mosley (pick-six) and Neville Hewitt intercepted Allen.