Asked this week how he thought Washington Redskins rookie quarterback Robert Griffin III would transition to the NFL, New Orleans Saints star Drew Brees described his fellow Texas native as “a winner,” and said: “It’s only a matter of time before he takes this league by storm. I just hope he doesn’t do it on Sunday.”

Griffin touched down in New Orleans, where both his parents grew up and where he spent a portion of his childhood, and had as fine an outing Sunday as he, the Redskins and their euphoric legion of fans could have imagined, leading his team to a 40-32 stunner over the Saints. The Redskins’ defense forced the Saints into an uncharacteristically disjointed outing that included 12 penalties.

After posting a near-flawless showing in the first half, Griffin played more of a caretaker role in the second half. His NFL debut ended with him completing 19 of 26 passes for 320 yards and two touchdowns. He also rushed for 42 yards on 10 carries on a variety of designed keepers and option plays to give the Redskins’ offense a new dimension. The team’s 40 points are the most scored by the Redskins since Mike Shanahan took over as coach in 2010.

“It was definitely loud, first of all. You could feel it in your body, the amount of loudness,” Griffin said. “The guys told me it was going to be like that – the loudest place I’ll ever play in – but why not? It’s New Orleans and the Superdome, so we came out and played big in a big arena, big stage and did a good job.”

Shanahan and Washington’s other decision-makers believed that Griffin had big-play capability when they pulled the trigger in March on a blockbuster trade that sent three first-round picks and a second-rounder to the St. Louis Rams for the No. 2 overall pick in the draft.

But despite his potential, questions remained about how quickly Griffin would make his presence felt. It didn’t take long. By the time the clock struck triple zeros, the Superdome crowd of 72,180 that had reached a deafening pitch just before kickoff, filed out almost in silence.

A cluster of rowdy Redskins fans descended to the lower rows of the stadium and began singing “Hail to the Redskins” as the team headed off the field and to the locker room. Griffin, who high-fived fans, was the last player into the tunnel as the fans cheered for him.

Griffin connected with eight different receivers – Pierre Garcon led the way with four first-half catches for 109 yards and a touchdown before leaving with a foot injury – to keep the Saints guessing. Rookie Alfred Morris had a solid debut, starting at running back and collecting 96 yards and two touchdowns on 28 carries. And place kicker Billy Cundiff was a perfect 4 for 4 on field goals in his first official game as a Redskin.

“Robert did an unbelievable job,” Shanahan said. “For him to play the way he did in his first game in the National Football League, with the poise that he played [with] and some of the throws that he made, and to execute the offense in this environment. . . . They threw a lot at us, very well-coached team. And to come away with the win and the way we played, it was a big plus for our guys.”

But the biggest surprise of the game may have come from the Redskins’ defense.

After struggling with consistency and injuries in their secondary throughout the preseason, the Redskins seemed overmatched as they prepared for Brees and the Saints, who last season boasted the top offense in the NFL.

With weapons such as Marques Colston, Darren Sproles, Jimmy Graham and Devery Henderson, Brees – who last season set the NFL’s single-season passing record – and the Saints were favored to beat the Redskins by 9.5 points early in the week. Washington was forced to make do without starting strong safety Brandon Meriweather while other defensive backs still were growing accustomed to their roles in the Redskins’ revamped secondary but held Brees to a 46 percent completion rate.

Brees threw three touchdown passes and two interceptions. The defense held the Saints’ offense to 25 points, nine below last year’s average, with another New Orleans touchdown coming on a blocked punt. The Saints mustered only 32 rushing yards.

Linebacker London Fletcher and the defense survived a some late-game heroics by Brees, who completed a 33-yard touchdown pass to Lance Moore with 6 minutes 19 seconds left, and a two-yard toss to Sproles to pull the Saints to 40-32 with 2:25 to play.

The Redskins twice denied Brees in the final six minutes of play, however. DeJon Gomes, who started in place of Meriweather, picked off Brees in the middle of the field and returned the ball 49 yards before he was run out of bounds at the New Orleans 3-yard line. That set up Morris’s second touchdown and gave Washington 40 points following the point-after.

With two seconds left on the clock, safety Reed Doughty came down with an interception at the goal line as the Saints tried a last-second Hail Mary pass.

“Going into the game, everyone was worried about the secondary, and rightfully so, when you lose two safeties . . .but I thought those guys competed, [Gomes] and [Doughty] when he went in, I thought they did a nice job,” defensive coordinator Jim Haslett said.

The win was Shanahan’s 15th season-opening victory. His career record is now 15-4 — tops among active coaches.

Shanahan’s 19th season as a head coach got off to a promising start when Griffin opened the game by completing all six of his pass attempts on the Redskins’ first possession of the game. Washington held New Orleans’s pass rushers at bay by running a series of quick-hitting swing passes and bubble screens to both sides of the field.

The drive stalled at the Saints 19-yard line when Griffin and Morris botched a handoff. Griffin scooped up the ball and turned upfield, but was stopped for a five-yard loss. The Redskins wound up settling for a 37-yard field goal by Cundiff.

The Saints shook off their game-opening struggles to put together a seven-play, 80-yard drive capped by a 20-yard strike from Brees to Graham.

New Orleans needed only 3:16 to find the end zone on that drive. But Griffin & Co. did even better. Backed up at his 12-yard line following the Saints’ kickoff, Griffin took his first downfield shot of the game and connected with Garcon, who made a leaping catch at midfield, then turned and raced 88 yards into the end zone.

Griffin took a hit that knocked him to the ground just as he let the ball go, but got up quickly. It was the longest pass play for a touchdown for the Redskins since the strike-shortened 1987 season, when replacement players Ed Rubbert and Anthony Allen connected for an 88-yard touchdown.

Griffin completed his first eight passes. He went into halftime with a perfect quarterback rating, becoming the first rookie quarterback in NFL history to post a perfect passer rating in the first half of his first game. For the game, Griffin had a 139.9 quarterback rating.

“This is a good start,” Shanahan said. “By no means did we play perfect, but I like the direction we’re going. We had some new pieces, some skill that gives us the chance to get some big plays. Robert not only executed the offense, but also had two or three plays that were off-balance that only a great athlete could make.”

Griffin said that “at the end of the game, [Brees] told me he was proud of me. That’s big for him to say that after they just lost the game.”