The Muggles just can’t resist the pull of these wizards

“HARRY Potter” star Daniel Radcliffe stood on Hollywood Boulevard in his dapper gray suit and polka dot tie, woozy from jet lag and the hot afternoon sun, marveling at the hordes of “Potter” fans screaming his name.

Los Angeles, he said, moments later, is “a town I can’t quite get my head around.”

Welcome to the club, mate. This, the home of real rabid fan worship, is a throbbing dreamscape that gives everyone a bit of a headache.

Even seasoned pros like the elfin Radcliffe, the winsome Emma Watson and mellow Rupert Grint were nearly overwhelmed by the fan love washing over them outside Grauman’s Chinese Theatre on Sunday at the L.A. premiere of “Harry Potter and the Order of the Phoenix.” The film, the fifth in the “Potter” series, opens worldwide on Wednesday -- about three weeks before the last book in the series is published. And a whole gaggle of Brits made the trek to L.A. to promote the Warner Bros. picture.

They dutifully worked the red carpet, chatting up everyone, including the Sci Fi Channel and the fan website Mugglenet.com. Imelda Staunton in a tidy lavender suit gamely served up the precious little giggle that makes her character Dolores Umbridge so deliciously evil. And there was costar Chris Rankin, who plays Ron Weasley’s brother Percy, bragging about his upcoming holiday on Santa Monica Beach. Nearby, director David Yates, who has signed on to direct the next film in the series, patted the sweat from his brow and recalled the weeks he and screenwriter Michael Goldenberg spent poolside at the Chateau Marmont working on the film’s script.

Across the street from the theater, people stood about 10-deep for a block waving their signs (one read “Trust Snape”) and wearing their “Harry’s My Homeboy” T-shirts. Their screams were so deafening that the actors were barely audible to reporters standing inches away.

This, Watson said, is what you call “ ‘Potter’ mania.” Grint said he was shaking in his stars-and-stripes Chuck Taylors when he stepped up to the crowd to sign autographs. Radcliffe likened the experience to “sheer terror.”

“Before you get out of the car,” Radcliffe said, shooting his ice-blue eyes over at the crowd, “you have to prepare yourself for the screaming thing. I’ll never be completely cool with it.”

Radcliffe fans had a bit more than usual to scream about this year. Their idol got naked on stage in a London production of “Equus” that concluded in early June. A series of photos depicting nearly every inch of Radcliffe are still making the rounds on the Internet. When asked about the images, and the impression they made on the public, Radcliffe breathlessly defended them. “A lot of people were saying that was a really stupid thing to do,” he said. “It wasn’t. I don’t think it was. I maintain it was the right decision and it went down really well.”

All right then. Elsewhere on the red carpet, the star turnout was modest. Two stars of “CSI Miami” -- Eva LaRue and Emily Procter -- swanned past wearing deep tans and stilettos. Chatty “Hannah Montana” star Miley Cyrus was there in her skinny black jeans and white pumps. But, lest we mistake her for a “Potter” fan, Miley insisted she’d come only as a favor to her little brother. “I’ve seen the movies,” she said, “but I don’t really know if I understand completely.”

After the screening, hundreds of premiere guests were shuttled to Jim Henson Studios in three double-decker buses for a party. Warner Bros. pulled out all the stops, lavishing the space with Potter-esque decor. There was a Forbidden Forest, a Nine and Three-Quarters train platform and a room of moving portraits and changing weather. Umbridge’s meowing cat plates covered the walls of the bathrooms and guests walked through replicas of the green-flamed fireplaces that the wizards used as transport in the film. It was nearly midnight before the last stragglers headed home.

Miles away, fan Kristen Allen and her pals were sleeping off their all-night Potter vigil. They’d spent Saturday night parked on the sidewalk across from Grauman’s, awaiting their idols, wearing their Hogwarts uniforms. Their stake-out was ultimately fruitless. They didn’t get an autograph or a handshake. And after the premiere, Allen looked beaten, her mascara smeared, her Hogwart’s tie askew. She hadn’t eaten a real meal in 24 hours.

But she and her friends weren’t daunted. They were coming back Monday to watch Radcliffe and the gang sink their hands and wands in the cement outside Grauman’s. Why does she go to all the trouble? Allen could muster only the simplest reply, “It’s just fun.”

gina.piccalo@latimes.com