Sam Darnold. (Rey Del Rio/Getty Images)

Things could not have gone much worse for Sam Darnold, the prized rookie quarterback of the New York Jets, on his first NFL play. If a textbook example ever is needed for phrases such as “ill-advised throw” and “rookie mistake,” Darnold provided it, handing the Detroit Lions a gift of a touchdown with a bad-decision, bad-pass interception. It all was very Jets-like.

But what happened from there was distinctly non-Jets-like. Darnold steadied himself and was very good in his NFL debut. And the Jets turned their night of high hopes and great expectations into honest-to-goodness positive results, sprinting to a 48-17 triumph over the Detroit Lions before a “Monday Night Football” television audience.

Who were those guys dressed in Jets uniforms? They could not have been actual Jets players. Things are not supposed to go this well for the Jets.

There undoubtedly will be rookie-year ups and downs for Darnold, the No. 3 overall selection in this year’s draft and the only member of this celebrated class of rookie quarterbacks to be a Week 1 starter. But who knew they would come in such rapid succession, all in the same game?

The start to Darnold’s NFL career was as ignominious as it gets. He joined a group of quarterbacks that includes Brett Favre in 1991 and Jameis Winston in 2015 by throwing an interception for a touchdown on his first NFL pass. Darnold moved to his right and committed the cardinal NFL sin of lobbing a high pass all the way back across the field to his left in the direction of running back Bilal Powell. Lions defensive back Quandre Diggs made the easy interception and raced to the opposite end zone.

But Darnold is calm and unflappable for a rookie. He didn’t wilt. He barely seemed to notice, in fact. He completed 11 of 14 passes for 122 yards and a touchdown over the remainder of the first half. He made an on-target deep throw to wide receiver Robby Anderson for a gorgeous 41-yard touchdown.

Darnold added a third-quarter touchdown pass to wideout Quincy Enunwa in a 16-for-21, 198-yard passing performance. And he had plenty of help. The Jets intercepted Lions quarterback Matthew Stafford four times. They scored touchdowns on an interception return and a punt return in a 31-point third quarter. Those 31 points went unanswered by the Lions after Detroit tied the game at 17. The Jets matched their road victory total from last season (with one) and set a franchise record for points in a road game.

It was an ugly head coaching debut for the Lions’ Matt Patricia, the former New England Patriots defensive coordinator hired after the team dismissed Jim Caldwell following a 9-7 season. It was a rough night for Stafford, who limped around after hurting his left knee and later exited the game temporarily after a jarring hit to his midsection. The Lions heard boos from their home crowd.

But this was more about Darnold and the Jets than it was about Stafford, Patricia and the Lions. This was a night for optimism for a franchise that far too often has had far too little of it. Not every night will be this good and this promising for Darnold. It’s doubtful that the Jets will be a legitimate challenger this season to the Patriots, winners of nine straight and 16 of the last 18 AFC East titles.

But on this night, at least, the Jets and their fans were completely justified in believing that there are big things to come with Darnold at quarterback.

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