SAN FRANCISCO

THE TEMPTATION is to shrug your shoulders and tell yourself that it's only the Lions, that the 49ers are just the latest NFL team to abuse the lost kittens of Detroit.

Why, then, all the noise in the 49ers postgame locker room? Why all the roaring and chanting and cheering and clapping after San Francisco's 31-13 win Sunday before 67,249 delighted fans at Candlestick Park?

Because the 49ers know what it's like to be being serially abused. They know how it feels to be searching for an identity, a touchdown, or a simple first down. Victories were few, impressive victories practically nonexistent.

The 49ers last won by more than two touchdowns in 2003, some 70 games ago, the first of Dennis Erickson's two seasons as head coach, the last of Jeff Garcia's five as starting quarterback. Kevan Barlow was a 1,000-yard runner. Terrell Owens, Fred Beasley and Julian Peterson represented the team at the Pro Bowl.

So this day was, for these 49ers, Mike Nolan's Niners, an entirely new experience.

Something is building. It's too soon to know what — or how far it will go — but the 49ers suddenly are ... interesting.

"This is fun,'' said wide receiver Arnaz Battle, a rookie in '03. "Football is fun for us right now. We have confidence in what we're trying to do and in the people trying to get it done.

"We're onto something. We have a legitimate team here. The personnel department did a great job in the offseason and bringing in coach (Mike) Martz has made a big difference.''

Indeed, Martz is making an impact. The offensive coordinator arrived in the offseason with a rep for imagination, asked to make the offense credible, if not feared. Three games into his tenure, offensive credibility is closer than it has been at any time in Nolan's three-plus seasons.

If San Francisco's 33-30 overtime win last week in Seattle presented an emerging unit, capable of piling up points, this four-touchdown game was a continuation — with the addition of quality defense.

The consecutive 30-point games for the 49ers are a first under Nolan. He's now 18-33 as head coach.

Moreover, he is 2-1 with Martz handling the offense.

Yet Nolan tore through his postgame news conference as if he had a chip on his shoulder and a personal jet idling in the parking lot. He credited his players and staff, citing his focus on next Sunday's game at New Orleans as the reason he was not more visibly pleased.

Maybe he recognizes the Lions are one of the worst teams on the planet and already fears comeuppance against the Saints.

The coach should be elated. His team is above .500, tied with Arizona for first place in the NFC West. Though Detroit is woeful, perfectly capable of going winless, Nolan is in no position to look down upon a rout — regardless of the opposition.

His players seem to comprehend this. They clearly were enjoying the moment, with some evidently buying into the team's direction.

"The captain of the ship is calling great plays,'' running back Frank Gore said of Martz. "As long as we pay attention, study hard, there's no reason we can't get better each week. That's the type of guys we have in the huddle and in this locker room.''

Martz is creating an offensive identity. Quarterback J.T. O'Sullivan is comfortable and competent in the offense. Gore, who rushed 27 times for 130 yards and caught four passes for 32 more, is a multipurpose weapon. Martz is finding ways to maximize functional receivers like wideouts Bryant Johnson and Isaac Bruce, as well as tight ends Vernon Davis and Delanie Walker.

"He's a genius,'' Battle said.

Whoa. That title, as it relates to Bay Area football, is reserved for the late Bill Walsh, the visionary 49ers coach and general manager, the man behind five Super Bowl championships. Martz, by comparison, is an assistant who can make the head coach look good.

Nolan never looked better, or smarter, than he did Sunday. For the first time, his team dominated. It was Detroit, yes, but for a 49ers team acutely familiar with low lows, no victory is beneath celebration.

Contact Monte Poole at mpoole@bayareanewsgroup.com.