NEW ORLEANS (AP) — David Carr walked gingerly out of the locker room and bent down slowly, grimacing and holding his back straight as he placed a set of headphones in the pocket of a suitcase.

Simply walking out of the Louisiana Superdome was a struggle once Sunday’s game against the Saints ended. But a combination of pain pills, shots, grit and inspiration drawn from his teammates gave Carr enough strength to lead Carolina to a come-from-behind 16-13 victory.

Carr hit Steve Smith for a game-tying, 17-yard touchdown in the fourth quarter, then hit Smith again to set up John Kasay’s 52-yard winning field goal as time expired.

‘‘It was by far the worst pain I’ve ever felt in my life,’’ Carr said of a first-quarter sack by Will Smith that knocked him out of the game for several possessions. ‘‘I felt like I got sat on and then twisted. Every bone in my back popped all the way up to my neck. … I didn’t know, honestly, if I’d ever play again.’’

He played again all right.

The Saints (0-4) held the momentum through much of the game and had repeated chances to pull out their first victory. Missed field goals, dropped passes, turnovers and untimely penalties cost them.

‘‘If we continue to make the dumb mistakes, drop as many passes, penalize ourselves on big plays, not take advantage of our field position, then it’s hard for the result to change,’’ said Saints coach Sean Payton, whose NFL Coach of the Year award last season now seems like a distant memory. ‘‘There’s a lot of blame to go around here and it’s not just the kicker. There are a handful of positions that we need to evaluate closely and make sure we’re playing the right guys.’’

Olindo Mare, playing through a sore groin, had a 20-yard field goal blocked early in the fourth quarter. And shortly before the 2-minute warning, Mare lined up again from 54 yards with a chance to give the Saints the lead, but missed.

Picked up in a trade from Miami, Mare has now missed four field goals this season. He was 2-for-4 against Carolina.

Drew Brees and Reggie Bush had the Saints’ offense looking better, but it wasn’t enough.

Mike Karney had the Saints’ only touchdown on a short run. Bush had 119 total yards on an array of running and short passing plays. Brees was 29-of-47 for 252 yards and two interceptions, but the second interception was not his fault.

He hit Devery Henderson on a long pass late in the fourth quarter, but the ball bounced out of Henderson’s hands and into the arms of defensive back Chris Harris.

Mike McKenzie’s interception of Carr’s throw gave the Saints another chance, but they couldn’t move the ball, forcing Mare’s failed long field goal attempt.

On Carolina’s next possession, Smith fought for 4 yards through two tacklers to turn a short catch into a crucial first down, then Kasay drilled the game-winner two plays later.

Panthers players mobbed Kasay at midfield, along the edge of the Saints’ fleur-de-lis emblem that is quickly turning from a symbol of civic pride into one of futility.

The Saints were supposed to be a Super Bowl contender, but now their chances of even competing for a playoff spot are extremely slim. Only the 1992 San Diego Chargers have fought back from an 0-4 start to do that since the NFL went to a 12-team playoff system in 1990.