WHEN you’re a King, you get a second chance.

At Webster Hall on Wednesday, the Kings of Leon redeemed themselves after what the band admitted was a lackluster gig the previous night at Irving Plaza. At Webster, the quartet of Tennessee kinfolk played an inspired 90-minute set of amp-crushing rock ‘n’ roll that lay somewhere between bluesy Led Zeppelin and funky Black Crowes.

Whether it was the band, the club or the audience, the concert explained why U2 selected the Kings as the warm-up act on the American leg of the Vertigo tour.

The show mixed material from the band’s first disc and its just released “Aha Shake Heartbreak,” and the tunes from the latter best moved the fans. It seemed everyone checked his too-cool-to-dance attitude at the door, and with each song, the band built momentum that carried through to the encore of “Novocaine” – a fitting closer for a band obviously feeling no pain.

To tag the Kings merely as Southern rock is only half-right. Despite their backwoods image, there was a sophistication to the music, especially in the lead guitar work of Matthew Followill. In every song, this guy was able to rip a solo that complemented the piece without ever stepping on his bandmates.

His brother, Caleb Followill, sings every song from the back of his throat, as if he’s gargling the lyrics. You can hardly understand a word he sings, but after a dozen songs, it was hard not to like the way he sounded.

Like his mug, his voice isn’t pretty, but it fit the stripped-down rock. Over thumping bass and crashing guitars, he sang about sex, drugs and rock ‘n’ roll excess. The song “Soft” was among the most X-rated, while the other tunes were merely drenched in debauchery. At least that’s what the few words that percolated to the top seemed to indicate.

Still, at this show, singer and fans best clicked on songs with howled choruses, like “Taper Jean Girl.” When they chanted, “Aha, hey hey” together, there was real chemistry.

The band creates its charisma through music. Nobody in this royal family has a movie-star kisser, the between-song patter is dysfunctional at best, and the clannish atmosphere onstage among the brothers and cousins separates them from the audience.

But when they played, the songs connected into extended jams that walked at first and eventually swaggered with fast guitar rhythms and blurred-stick drumming.

There were no mopey ballads or Valentine sway-songs. This was a rowdy roadhouse show in the heart of the city.

In a way, this approach has hurt the band over the years, since the poke-’em-till-they-pop attack doesn’t lend itself to radio-friendly singles and, worse, attracts more guys than girls.

Still, with a record as good as the one just laid down and the exposure they will get opening for Bono and the boys, the Kings might finally get their due.