Daniel Radcliffe in The Cripple of Inishmaan
(©Johan Persson)

His face may be prominently displayed on the Playbill cover and theater marquee, but Daniel Radcliffe melts seamlessly into the ensemble of The Cripple of Inishmaan, Martin McDonagh’s 1996 play now receiving its Broadway premiere after two acclaimed off-Broadway productions. Director Michael Grandage’s revival, imported here after a successful London engagement, fully mines the dark humor of this quintessentially Irish work in which the characters’ perverse cruelty takes on an air of mordant poetry.

In his most accomplished stage performance to date, the Harry Potter star delivers a physically and emotionally committed turn as “Crippled Billy,” an orphaned 17-year-old whose useless arm and stiff leg reduce his gait to a painful shuffle. In this play, inspired by documentary filmmaker Robert Flaherty's arrival on the bleak island to film his 1934 film Man of Aran, Billy finds his life briefly transformed when he is whisked off to Hollywood for a screen test.

But before that happens we are introduced to a gallery of colorful characters: Billy’s unmarried aunts Eileen (Gillian Hanna) and Kate (Ingrid Craighe), who run a general store whose stock seems to consist almost entirely of canned peas; the endlessly gossipy Johnnypateenmike (Pat Shortt), who constantly regales the townspeople with stories both big (Hollywood coming to town) and small (a petty incident involving a goose); his elderly mother (June Watson) who he keeps perpetually supplied with booze; red-haired spitfire Helen (Sarah Greene), with whom Billy is hopelessly besotted; her younger brother Bartley (Conor MacNeill), who she tortures unmercifully; and the town doctor (Gary Lilburn) who clearly has his hands full.

There’s little plot to speak of, and the two-and-a-half hour play proves repetitive in its depiction of its characters’ many quirks. But much like Flaherty fictionalized many elements of his so-called documentary, McDonagh portrays the illusions of these colorful figures who are nearly always saying one thing while meaning something else entirely.

To say that the members of the ensemble work together seamlessly is an understatement. The mostly Irish performers deliver such authentic-feeling, lived-in turns that it’s easy to imagine that their characters have lived in a state of not-so-peaceful co-existence for their entire lives. Their casual harshness is well illustrated in the aunts’ reaction when they’ve discovered that Billy has snuck off to Hollywood.

“I hope the boat sinks before it ever gets him to America,” one of them declares. “I hope he drowns like his mammy and daddy before him,” the other agrees, before adding, “Or are we being too harsh?”

While Greene is a standout as the sexy Helen for whom physical abuse is her natural way of expressing herself, it’s indeed Radcliffe who steals the show. His Billy displays a complex mixture of steeliness and vulnerability, the latter heartbreakingly conveyed when he finally musters up the courage to ask Helen out on a date only to be met with harsh laughter. It’s a brave, self-effacing turn that well demonstrates this young actor’s admirable willingness to go out on a withered limb.

Cort Theatre, 138 W. 48th St. 212-239-6200. www.Telecharge.com. Through July 20.