LONDON - Harry Potter is all grown up.

Daniel Radcliffe, who plays the boy wizard in the film adaptations of J.K. Rowling's bestselling novels, sheds his magician's robes -- and everything else -- for his West End stage debut as a troubled stable boy in Peter Shaffer's "Equus."

Even before Tuesday's opening night, the Internet is awash with anticipation and outrage. In the play, Radcliffe strips naked. He simulates sex. He smokes.

Radcliffe, 17, has said he took the role of Alan Strang, a disturbed young man whose obsession drives him to blind horses with a metal spike, partly from a desire "to shake up people's perception of me."

On those grounds, the play is already a success. Hundreds of Potter fans have swarmed the theatre during previews. Canny marketing -- including carefully cropped publicity photos of Radcliffe's naked torso -- has helped the production sell US$3.1 million worth of tickets in advance.

But not everyone is happy.

The anti-smoking group ASH said Radcliffe's onstage cigarette was "regrettable." The group said it feared Radcliffe's status as a role model might encourage young people to start smoking.

Warner Bros., the studio behind the Harry Potter films, issued a statement in response to reports it was unhappy with Radcliffe's edgy new image. The studio said it considered Radcliffe a "great collaborator" and "fully support(s) him in the artistic choices he makes as an actor."'

Radcliffe said he saw the stage nudity that comes with the role as "a rite of passage."

"That iconic scene is the physical and emotional climax of the play," he was quoted as saying by The Daily Telegraph newspaper. "So if I do that with pants on, it would be crap."

He said he took the part in a bid to move beyond Harry and assert his acting credentials.

"With this, they can say I'm good or terrible but the one thing they can't say is I haven't challenged myself," he said, according to the report.

"Equus" opened in 1973 at London's National Theatre, before a successful run on Broadway starring Anthony Hopkins. Richard Burton and Peter Firth starred in a 1977 film adaptation.

The new production co-stars Richard Griffiths -- Harry's dastardly Uncle Vernon in the Potter movies and a Tony Award winner last year for "The History Boys" -- as a psychiatrist who interviews the troubled youth.

Radcliffe returns as the teenage wizard in "Harry Potter and the Order of the Phoenix," slated for release July 13. The sixth Potter film, "Harry Potter and the Half-Blood Prince," is due to start filming this summer, after the run of "Equus" ends in June.