LANDOVER, Md. -- The day began as a celebration of change, with Josh Harris in as the Washington Commanders owner and Dan Snyder out. So, back came the alumni and the fans, embracing the new era and filling the stadium.

Before the game, some of the organization’s former greats met with fans signing autographs and smiling for photos as a band played on, capturing the mood of the day with their version of “In the Air Tonight.”

The day ended with a celebration, too. The Commanders rallied to beat the Arizona Cardinals 20-16 in what the players acknowledged was a lackluster showing, but still a win. It also ended with Harris receiving a game ball, his third of the year but first for a regular-season victory.

Harris purchased the team from Snyder this summer, bestowing hope upon a franchise that had mostly struggled during the previous owner’s 24-year reign.

Shortly after an agreement was announced in May, fans started buying more tickets. The team announced a sellout for the opener two weeks ago. On Sunday, they announced the crowd at 64,693. For a change, almost all the crowd was rooting for Washington from the moment saxophonist Mike Phillips finished a stirring rendition of the national anthem until the final tackle of the game on a punt return.

“It was amazing,” Washington receiver Terry McLaurin said. “I got chills standing there for the national anthem. That dude can play, the way he played through the planes coming over, the roar of the crowd. I’ve been here five years and that was probably the loudest I’ve heard it.”

Washington needed all the positive vibes it could get after turning the ball over three times in the first half and trailing 16-10 midway through the third quarter. At times a few boos could be heard as the offense jogged off the field.

But the Commanders rallied as the defense recovered two fumbles in the fourth quarter, with the offense turning them into 10 points.

“Our guys fed off the energy,” Washington coach Ron Rivera said.

Harris has talked often about turning FedEx into the home-field advantage the franchise once enjoyed at RFK Stadium during its most successful seasons. Rivera has said the same for a few years. Sunday, Washington saw what it could be once again.

“The fans being engaged like this is absolutely wonderful,” said former Washington quarterback Joe Theismann, who helped lead the team to its first Super Bowl victory after the 1982 season. “That’s something that’s very special. It speaks to the volume of the enthusiasm that’s always been here. If you were part of this football team for the last three or four or five years it’s something you’ve never seen.”

Or longer.

“It was really electric,” tackle Charles Leno Jr. said. “It was fun. It was a great environment.”

Defensive tackle Jonathan Allen told fans at an event in July following Harris’ takeover he's “been waiting seven years for this.” This, of course, was a packed stadium rooting for one team.

He said after the game it was what he’d hoped.

“1,000%,” Allen said. “They were incredible. I only expect it to get better from here. As players, we have to make sure we do our job to give them a reason to continue to come out and support.”

But the day also marked the return of former players such as Hall of Famers John Riggins and Champ Bailey as well as former quarterback Robert Griffin III, the 2012 NFL offensive rookie of the year. Riggins had not been back in a while; Bailey and Griffin returned for the first time as retired players. Numerous other alumni attended, including Hall of Fame quarterback Sonny Jurgensen.

Bailey was mobbed by fans and introduced on the field as the Legend of the Game. Griffin once again heard chants of “RG3! RG3!” as he waved to the crowd, or while signing autographs 90 minutes before kickoff.

“Just grateful,” Griffin said. “There's a reason that a lot of alumni stayed away and we don't have to talk about that anymore. But now it's a fresh start. And to be able to come here today and see the reaction from the fans and talk to you guys [media] again, it feels like just really grateful to be back and get a chance to be a part of a team and a winning organization.”

But while Sunday was a celebration -- on Friday Harris called it a playoff game for him -- there was also a reality check. Washington might be 1-0, but it beat a rebuilding team in the Cardinals playing with a quarterback it acquired two weeks ago.

At some point the enthusiasm over the ownership will change if the Commanders don’t build on this win, starting Sunday at the Denver Broncos (4:25 p.m. ET, CBS).

“We do appreciate them coming out,” Rivera said of the fans, “but we have to be a better football team for them.”