CHARLOTTE — In my 17 years covering the Carolina Panthers, I can honestly say I've never seen a loss greeted with more happiness by fans than the 28-21 season-opening defeat the Panthers suffered to Arizona Sunday.

One name and one number explain the reason: "Cam Newton" and "422." The Panthers' rookie quarterback threw for a startling 422 yards in his debut and accounted for all three Carolina touchdowns in a game that instigated another full-fledged episode of "Cam Mania."

It feels sunnier around the Carolinas this week after the darkness of the 2-14 season of a year ago, and much of that is thanks to No. 1. The Panthers lost their first game Sunday but grabbed a double helping of hope.

Newton made just about everyone ecstatic Sunday - his coaches, his teammates, his sponsors, his fans. Just not himself. He was down. He hadn't lost a game that counted since 2009, when he was in junior college, and he couldn't get the Panthers into the end zone on their final drive despite running five straight pass plays at or inside the Arizona 11.

But man, he was still really good.

Even while trying to temper expectations of Newton, Panthers coach Ron Rivera was still very peppy Monday. Had Newton surprised him in his debut?

"Pleasantly, yes," Rivera said. "Did we expect him to have great flashes? We did. But he had a whole bunch in a row. ... Did he exceed our expectations? Yes, that's probably the best way to put it. He surprised a lot of people who didn't believe in him."

Then came Rivera's warning. "Now that was just one game," the coach said. "He could take a step back. Because people are going to gear up for him, see what we're doing with him and are going to attack that now, too."

It is entirely possible that a Green Bay team still stinging from giving up 419 yards passing to Drew Brees and 34 points to New Orleans will derail the Newton train in five days in Charlotte. Certainly, the reigning Super Bowl champions will play better defense than Arizona did, and the Packers' blitzes will probably be even more incessant than the Cardinals.'

But Newton is just so darn strong. He throws so well off his back foot and on the run. The Panthers correctly used him more in the shotgun Sunday, even on a goal-line play from the 1 where he took a direct snap and then dove in for the score.

Offensive coordinator Rob Chudzinski kept letting Newton have a longer leash as the game went on, as Carolina threw the ball 37 times and ran it only 27 because the pass was so much more effective.

Newton's average preseason was quickly swept aside by the flood of numbers. He threw for the most yards ever for a rookie quarterback in his first start and had a 110.4 quarterback rating. As of Monday afternoon, he also led the NFL in passing yardage.

But I thought the most significant number was that Newton completed eight passes of 20 yards or longer. The Panthers averaged 1.9 pass plays per game of more than 20 yards in 2010, so Sunday literally constituted a month of big pass plays for last season's team.

Newton made some mistakes, too. He threw his one interception into double coverage and had a second pickoff nullified by a penalty on the Cardinals. He also drew a 15-yard penalty for excessive celebration after his rushing touchdown.

"It's not good enough yet," Rivera said Monday, speaking generally of the offense. "Even Cam - it's not quite good enough."

Nevertheless, the hyperbole was in full tilt.

An ESPN.com writer compared Newton's debut favorably to the all-time best debuts of anybody ever, rating it better than Harper Lee's "To Kill a Mockingbird" and LeBron James' 25-point debut as a rookie, but behind the appearance of "The Beatles" on Ed Sullivan.

The "We Were Wrong on Cam" chorus added a number of voices. There were the hundreds of thousands of fantasy football owners scrambling to pick up Newton after a week in which he scored more points than practically every other NFL quarterback.

Yahoo Sports sent out a press release noting that Newton was drafted in only 12 percent of the fantasy football leagues it runs but now is on a roster in nearly half of them, having been added to more than 75,000 teams in the past 24 hours.

There was former NFL MVP Kurt Warner, who had said on the NFL Network right after Newton was drafted: "Franchise quarterbacks have to be able to play in the pocket. He's a long way from that right now."

Warner tweeted Sunday: "Big enough man to admit when wrong: Cam Newton is impressing me today! Said he wouldn't be ready, but sure looks like he is to me!"

There was ESPN.com columnist Gene Wojciechowski, who wrote the night Newton was drafted that the Panthers overreached. "I wouldn't have touched him at No. 1 with a goalpost," Wojciechowski wrote then. "Newton is a walking red flag. ... I question his past. I question his future."

On Sunday, Wojciechowski was in Arizona for the 422-yard game and declared Newton's first game a "revelation." He wrote: "It was the kind of game - even though his team lost - that made you think, He can't make it look that easy, can he?"

On Sunday, Newton might not. Rivera's warning that he might take a step back will prove prescient, and soon.

But to those who lived through the 2010 season, it felt about as nice as a loss ever can.

sfowler@charlotteobserver.com; 704-358-5140