The New Orleans Saints, left for dead by so many at the beginning of this season, have instead hit the season’s halfway mark alive and thriving.

And their franchise quarterback is as dangerous as he’s ever been.

Behind a vintage performance from Drew Brees that ranks among the best ever, the Saints rode an unstoppable offense and a miraculous final sequence to outlast the New York Giants 52-49 on Kai Forbath’s 50-yard field goal, ending a wild game that featured the third-most points in NFL history.

“This was certainly one of the craziest games that I’ve ever been a part of,” Brees said. “To be on the winning end of it and keep a three-game streak alive at the midway point of the season is something special, and I still feel like our best is yet to come.”

Three weeks ago, the Saints (4-4) were declared all but dead, prompting national speculation about Sean Payton’s future in New Orleans, the potential decline of Brees and doubts on the roster renovation that took place in the offseason.

“We know what we have inside this locker room, and we stuck together,” receiver Brandin Cooks said. “It doesn’t matter what’s going on outside of the building. ... You can’t lose your confidence in this game. We put so much work in, we knew sooner or later our time was going to come.”

Brees, the franchise quarterback who has turned in so many big days at the helm of the Saints, has taken arguably the most heat. Now 36, Brees has been the target of talk about his decline, questions about his contract and speculation that he could be traded, a move that would bring the best era in the franchise’s history to an end.

The legend answered those questions emphatically Sunday.

After missing an early deep ball to a wide-open Cooks, Brees rarely missed again, completing 40 of 50 passes for a career-high 511 yards and seven touchdowns, tying an NFL record for TD passes in a game.

Brees hit Cooks twice for touchdowns, tossed two more to Willie Snead and spread around one apiece to Ben Watson, Marques Colston and C.J. Spiller.

“We were just in the flow of the game, and every time we got the ball, there was a big sense of urgency in terms of just being efficient to go down and get points and score touchdowns,” Brees said. “You just kind of shake your head at how it all transpired.”

The problem was that the Giants’ Eli Manning matched Brees throw for throw.

Despite a consistent pass rush that kept the New Orleans native under fire, Manning shredded the Saints secondary for 350 yards and a career-high six touchdowns — combining with Brees for the most touchdown passes in a game — including three to fellow New Orleans native Odell Beckham Jr., who finished with eight catches for 130 yards.

Manning kept the Giants in the game. Shortly after taking a huge hit from Bobby Richardson that could have produced a game-sealing fumble — a controversial defensive holding on Delvin Breaux wiped out the turnover — Manning fought through the pain to find Dwayne Harris for two touchdown passes to tie the score at 42.

Then the Giants secondary made a play. With Brees on the move again, Dominique Rodgers-Cromartie dislodged the ball from Snead, the ball popping right into the hands of Trumaine McBride for a 63-yard touchdown return that gave New York a 49-42 lead.

And that’s when Brees, who has always been able to come back, came up big again, directing a 14-play, 80-minute drive that finished with a record-tying touchdown pass to Spiller and robbed the Giants offense of any time on the clock, handing the ball to Manning with less than a minute.

Overmatched all day, the New Orleans defense needed a stop.

“You’ve just got to stay focused,” safety Jairus Byrd said. “You’ve got to believe. The way the game was going, we knew it was going to come down to our defense holding them, and fortunately, we were able to do that.”

New Orleans forced a three-and-out and a punt that ended up being the difference.

First, rookie return man Marcus Murphy came up big, picking his way through the Giants for a 24-yard return, only to fumble the ball into the hands of Snead, whose face mask was grabbed by punter Brad Wing on the way down.

By virtue of the penalty, the Saints had one chance at a field goal for Forbath, a 50-yard attempt that would be the veteran’s first as a Saint and match his career long.

Forbath split the uprights, ending one of the wildest games in franchise history.

“What else do you want besides a game-winner?” Forbath said. “That’s what kickers live for.”

Now the Saints head into the season’s second half 4-4, with a winnable slate of games on the horizon and a chance to get back in the hunt for a wild-card berth.

“There’s going to be so much outside noise, and that’s the same thing going forward. People are happy; people are willing to harp on the great points now that we’re back to .500, we’ve put three wins together,” defensive end Cam Jordan said. “The sky is no longer falling.”

Not by a long shot.