It’s tough sustaining bold punk

Green DAY looked like a veteran prizefighter Tuesday at the Long Beach Arena -- one who had fought back to reclaim his title, then just as he was ready to deliver the knockout punch, decided to drop his gloves and show the crowd he could juggle too.

The long-running Bay Area punk band has crafted a boldly ambitious state-of-the-disunion pop-punk opera with its latest album, “American Idiot,” a rejuvenating work that debuted at No. 1 on the national charts after its September release.

With the authority the trio has earned as possibly the bestselling punk band ever, Green Day took the stage following a wall-rattling recorded introduction that used the theme from “2001: A Space Odyssey.”

Without a word, the band exploded into the new album’s title number and reeled off the first several tracks, demonstrating how well this outfit has moved into adulthood from its beginnings railing against things that give teens angst, i.e., getting dumped, being misunderstood.

Green Day provided a refreshing reminder of how potent punk can be in the right hands, especially on the heels of the polite but gutless third-generation punk from New Found Glory that preceded the headliner.

But instead of delivering “American Idiot” in its entirety, as singer-guitarist Billie Joe Armstrong, bassist Mike Dirnt and drummer Tre Cool did earlier in this tour, they detoured into a greatest-hits set that pleased the crowd but muted the effect of what they’d started. Especially when Armstrong indulged in such Rock 101 cliches as pitting the left side of the house against the right in a cheering contest.

In another segment that ran way too long, Armstrong drafted a drummer, then a bassist and finally a guitarist from the crowd to take over the performance mid-song. It was a populist move that underscored punk’s credo that “anyone can do this,” but it dissipated most of the steam the band had built up to that point.

Green Day still has the ability to make music that matters. If only the band could keep its attention on what matters long enough to finish the fight.