ATLANTA — Nick Sirianni heard about the disparaging remarks some made after his introductory news conference. How he looked nervous. How he fumbled over his words. How there’s no way that guy would be able to lead the Eagles and devise an innovative offense.

Well, that guy was not that guy. Go figure.

There had been signs with each successive interview, and more importantly, with every opportunity there was to see Sirianni on the field with his players and how they executed his schemes. But there was still the great unknown of how a first-time coach would fare once the lights came on.

We now know after the Eagles upended the Falcons, 32-6, at Mercedes-Benz Stadium: the franchise is in able hands with Sirianni. One game is just that. A Hall of Fame coach it does not make. But the Eagles looked like a team that bought into a coach who was anonymous in Philadelphia just nine months ago.

“You want to fight for him because he’s been the same guy since he got here,” Eagles defensive end Brandon Graham said. “He even joked the other day about his first time doing the media and how everybody ripped him and how mad he was.

“But at the same time, he was like, ‘You got to shake it off and come back and do it again.’”

The Eagles weren’t especially sharp Sunday. They committed 14 penalties. The defense missed a handful of tackles by the half. The offense left yards and points on the field. And Sirianni had a few dubious moments himself.

“We have to clean up the things that require no talent,” he said.

But they never dug themselves a hole they weren’t ready to climb out of. It helped that the Falcons appeared hapless. Arthur Smith doesn’t have the roster Siranni does, but the other first-time coach at the Benz — another offensive-minded coach the Eagles interviewed in January — didn’t look anywhere near as prepared.

Sirianni’s game plan wasn’t extravagant, but it was diverse. He mixed in some three-tight end and two-running back sets among a 48-36 percentage split of 11 and 12 personnel. He had variety in the run and pass games and featured various skill-position players.

There were multiple screens to Quez Watkins, Jalen Reagor, and Miles Sanders. There were run-pass options to Dallas Goedert and DeVonta Smith when the reads said pass. There were downfield shots to Zach Ertz and Smith. And there were plays designed to take advantage of quarterback Jalen Hurts’ athleticism.

Hurts played well — great, considering it was only his fifth career start. He completed 27 of 35 passes for 264 yards and three touchdowns. He ran seven times for 62 yards — some on designs, some on scrambles. But he played within himself for the most part and had zero turnovers.

Sirianni put Hurts and his players in position to succeed. He didn’t have his quarterback taking seven-step drops with four receivers running vertical routes all the time. He gave Hurts options at the snap, which is key against pre-snap disguising defenses.

“We wanted to execute some of that short, controlled passing game,” Sirianni said, “but also be able to take the ball down the field … [but] Atlanta did a good job of taking away and forcing us to throw underneath.

“We get a coverage that we want, then we have the ability to go down field, and if not, Jalen did a good job with his reads and taking what the defense gave him.”

» READ MORE: Eagles QB Jalen Hurts ‘in complete control’ as the offense impresses in season opener against Atlanta Falcons

The Eagles will need to win in different ways. Better defenses will counter what’s working, if not right away, with adjustments. But Sirianni’s offense — and, obviously, most good ones — are built to give answers when a first read or either the run or pass are taken away.

Doug Pederson’s offense once provided those answers, as well. But for various reasons they no longer did last season. Speaking of which, the 32 points the Eagles scored were three more than their highest output a year ago.

They could have had more. The Eagles passed up two makeable field goals when Sirianni went for it on fourth down. They failed on both occasions. You could quibble with the calls, but not with the aggressiveness.

On the first attempt in the second quarter — fourth-and-4 at the Falcons’ 36 — Sirianni said the analytics chart gave him the green light to pass up a 54-yard field goal try. But on the second in the third — fourth-and-2 at the 20 — it was a toss-up.

“The one, you could argue back and forth,” Sirianni said. “But with the way our defense was going … we got a three-and-out and we got the ball back and we scored a touchdown.”

That’s called going with your gut.

Sirianni had been questioned about the intensity, or lack thereof, of training camp, and about resting his starters in the preseason. But the Eagles didn’t seem gassed, and aside from a few minor injuries, they came out relatively healthy.

“Now you can see why he did what he did, holding us off for a little bit,” Graham said. “So we could fly around on game day.”

Sirianni had been planning for this moment his entire adult life. The 40-year-old native of Jamestown, N.Y., comes from a family of coaches, but he himself had never been the top dog. He said he called his father, his brother, mentor Frank Reich and other head coaches he knew last week.

He needed more advice on how to handle the first game, his first night-before. He showed movie clips, per usual, Saturday night. He told a story that he said was embarrassing, so he kept that in-house. And he delivered his message, one that had been referenced in how he handled the kerfuffle over his shaky first impression with Philadelphia.

“The whole message was about having a dog mentality,” Sirianni said. “Dog mentality, to us, means that no matter what happened on one play … play the next play. Be in the moment.

“And our analogy is, just like a dog would when you open up the cage and he goes to hunt.”

But unlike that metaphorical dog, when it came time for Sirianni to finally give his pregame speech Sunday, he paused for a moment.

“I had a moment with myself,” Sirianni said. “It meant a lot. I thought about the work that got me to this position.”

One down. More to go.