NFL

PERFORMANCE MAKES REX’S CHOICE EASY

MARK Sanchez by first- round knockout.

JETS BLOG

If Rex Ryan were forced at gunpoint to decide on his Opening Day quarterback today, Sanchez would be his man.

Sanchez (3-4, 88 yards) led the Jets to a touchdown on his one and only series and looked like 50 million bucks doing it.

A roar went up when Sanchez ran out to the huddle for the first time. It was 7:33 p.m. The scoreboard clock read 0:28.

Because of a personal foul against Jim Leonhard on the punt, Sanchez started at his 7. He wasn’t pinned there for long.

Offensive coordinator Brian Schottenheimer immediately sent in this message: Welcome to the NFL kid, now give us a Joe Namath moment.

Sanchez drops back to pass, looks left, pump fakes, and sees David Clowney sprinting down the right sidelines past cornerback Justin King . . . and drops a perfectly-thrown bomb in Clowney’s lap for 48 yards.

Another roar.

“That’s probably the hardest pass you can throw,” Woody Johnson said after Rams beat the Jets 23-20 last night at Giants Stadium. “It has to be accurate . . . you don’t want to underthrow it . . . you don’t want to overthrow it . . . it has to be like right on, so that takes a lot of calm to do. He made it. . . . It didn’t look like a rookie throw.”

“A great throw by Mark,” Clowney said.

Ryan removed Sanchez because of the battered offensive line.

“He’s a cool customer,” Ryan said.

A 14-yard completion underneath to dangerous Dustin Keller and another underneath dart that catch-and-run Keller turned into a 26-yard gain set up a one-yard Thomas Jones touchdown leap that gave the Jets a 10-3 lead with 11:40 left before intermission. Eight plays, 93 yards, 3:48.

You name it — poise, swagger, moxie, accuracy, leadership — Sanchez brought it all to the table.

“Definitely didn’t act like a rookie, like he’d been there 100 times before,” Keller said.

“He’s a relaxed guy,” Cotchery said. “Sometimes rookies get so excited after making a play, they can’t calm down but he was ready to move on to the next play.”

How’s this for calm?

“Mid-cadence . . . said all right, Green 30, boom, the mouthpiece came out, defense was laughing,” Sanchez said. “First play, what an idiot!”

After the completion, Sanchez matter-of-factly bent down and picked up his mouthpiece.

Kellen Clemens (4-4, 24 yards) fumbled away a field goal on the first of his two series when he was strip-sacked by Leonard Little and James Hall recovered at the Jets 27.

“I gotta do a better job of protecting it and stepping up into the pocket,” Clemens said.

Clemens, aided by a 28-yard Brad Smith reverse — Clemens dove at the heels of a penetrating Hall to assist — marched the Jets into field goal range on his next possession. His best moment came when he rifled a 12-yard out to the right sidelines to Jerricho Cotchery. Ryan praised him and No. 3 quarterback Erik Ainge as well.

Sanchez looked poised and decisive. Looked like The Natural. Looked as if he were quarterbacking USC again. Of course Sanchez is a long, long way from being The Next Namath. It doesn’t mean Jets fans should stop letting the imagination run wild.

The first glimpse of the kid who would become Broadway Joe came in an August, 1965 preseason Jets-Patriots rookie game in a high school stadium in Lowell, Massachusetts. The Sports Illustrated account: “Namath . . . performs with the sure grace and cool facility of a five-year man. He passed for two touchdowns and directed the team well (the Jets won 23-6), and only later, privately, while the team doctor who is never far removed from that knee fussed over him, did Namath show the pain that he does not publicly admit to.”

Namath started nine games as a rookie — 18 touchdowns, 15 interceptions, a 48.2 percent completion mark and 3-5-1 record — and won AFL Rookie of the Year honors in 1965. The Namath Era officially began when he replaced Mike Taliaferro in Game 3 and was 19-40 for 287 yards and two TDs in a loss to the Bills.

If Sanchez gets the start and outguns Clemens Monday night in Baltimore, Ryan will anoint him the starter. “I don’t think we’re there yet. We’ll meet as a staff and if there’s a decision to be made, we’ll all discuss it,” Ryan said.

First-round knockout.

steve.serby@nypost.com