Saints defense does just enough to confuse Atlanta Falcons

Quarterback Matt Ryan and the Atlanta Falcons entered Sunday’s season opener prepared to play against a patchwork 3-4 defense used by the New Orleans Saints.

Yet in the aftermath of the Saints’ 23-17 victory at the Mercedes-Benz Superdome, one got the impression that the Falcons had just exited a haunting “house of mirrors’’ devised by Saints first-year defensive coordinator Rob Ryan.

“There is always the unknown in Week 1,’’ Atlanta coach Mike Smith said. “You see a lot of unscouted looks, and they gave us a lot of different looks on the other side. That wasn’t the 2012 defense from last year.’’

No, it wasn’t — at least not Sunday, when a sold-out stadium welcomed back Saints coach Sean Payton to his first regular-season game since he served a season-long suspension for his role in Bountygate.

The outcome remained in doubt until Saints strong safety Roman Harper cradled a deflected pass in the end zone for a game-clinching interception with 43 seconds remaining. That put the exclamation point on a stellar goal-line stand reminiscent of Week 10 a year ago when New Orleans turned back a late scoring attempt by Atlanta to preserve a 31-27 victory.

On Harper’s pick on fourth-and-goal from the 3, the Saints doubled up Falcons wide receiver Julio Jones, brought four rushers (led by inside linebacker Curtis Lofton) and forced Ryan to throw into double coverage, in the direction of tight end Tony Gonzalez.

“They did to me what they had done to me all night down there (in the red zone),’’ said Gonzalez, who caught a 7-yard scoring pass from Ryan in the first quarter. “I got bracketed, double-teamed, and it worked out for them. I like my chances, usually. It was just a fingertip away from coming down with the ball.’’

Matt Ryan played well in defeat, completing 25 of 38 passes for 304 yards, with two touchdowns and one interception for a 96.8 passer rating. He was sacked three times and hurried other times by a variety of pressure packages.

“When they came with their ‘dime’ personnel, sometimes No. 41 (Harper) was a defensive lineman, sometimes he was a linebacker, sometimes he’d be a safety,’’ Falcons center Peter Konz said.

“I heard some of the guys talking about Lofton knowing our scheme because he played with us in Atlanta. The key was knowing who was going to be a rusher in their different fronts and who wasn’t, and it was hard at the end of the game when everything is a little jumbled.’’

Left guard Justin Blalock said the Falcons expected the Saints to show some “exotic looks’’ on defense because of recent injuries to players in their front seven.

“We knew they had some personnel issues that might have pushed them into crazy looks, but their guys were very flexible and were able to do a lot of things with their pre-snap looks,’’ Blalock said. “At the same time, we see a lot of multiple fronts from our defense each day in practice, so more often than not, we are able to see through the subterfuge and do what we need to do.

“But give them credit. They played extremely hard and really smart and made plays when they had to today.’’