Though titled “Evita,” Andrew Lloyd Webber’s and Tim Rice’s pop-rock opera spectacle now at Diamond Head Theatre clearly belongs to Che Guevara, the narrator.

Drew Niles makes an impressive island stage debut as Che, and he’s a director’s dream come true as well as an audience delight.

Che is technically a device — a smooth, charismatic, even-keeled commentator, observer and one-man Greek chorus, or “vox populi” (voice of the people). He’s a force of energy and a source of insights, in this sentimental and melodramatic portrait of Eva Duarte, the commoner who would become the second wife of Argentine President Juan Peron.

Niles, who physically resembles politico Paul Ryan, the prevailing speaker of the House, has a riveting and powerful presence — a tenor with depth, a nimble dancer and an intermediary for the Argentine population that adored and admired the first lady, whose ascent from obscurity to national symbol of hope and austerity is the stuff of legend.

Like Patti Lupone, who originated the Evita role in the 1979 Broadway production, and Madonna, the pop singer-actress who assumed the part in a 1996 film adaptation, Hawaii actress Jody Bill Bachler makes a significant showing as Evita, with a caveat. She has the looks, the manner and the swag of a politically driven first lady, and maintains those characteristic upright, outstretched arms as depicted in those iconic posters. Her mezzo serves her well in upper registers, but she occasionally sounds shrill. Indeed, Evita is a challenge — she died young, at 33 — with her tale beginning with her funeral, told in flashbacks.

Bachler possesses stamina, dancing with the chorus, projecting aristocratic and political superstardom. For director/choreographer John Rampage, she is a “find.” She hits the mark in the show’s classic signature, “Don’t Cry for Me Argentina,” performing from the balcony of the Casa Rosada, a highlight that earned hearty opening-night hurrahs.

Like Niles, she is a relatively fresh face, primed for more future leads.

Rampage, who also is DHT’s artistic director, reaches a pinnacle of his long and varied career, steering this endeavor — considering its checkered past with mixed reviews but earning seven 1980 Tony Awards, including best musical — to a triumphant finish. Like a military general, he moves choruses of adults and children, dancing men and women, Army officers and aristocrats in syncopated marches, and tango soloists Heather Taylor and Cal T. Chester with savvy precision.

Further, he has assembled a stellar ensemble led by Niles and Bachler, who display chemistry and charm on “High Flying Adored” and “Waltz for Eva and Che,” though Evita’s romantic fling is with Agustin Magaldi (played with flair by David Treacher), a Latino club singer. Other principals include Eli K.M. Foster (as Juan Peron), who projects that presidential aura, and Natalie Borsky (as Peron’s mistress), whose solo on “Another Suitcase in Another Hall” is one of Lloyd Webber’s melodic hits amid an occasionally bombastic score that — with its historical necessities — packs a bounty of lyrics by Rice that propel the storytelling, sung opera style.

Emmett Yoshioka’s eight-member orchestra sounds double the size. Willie Sabel’s pristine two-level set boasts seven arched windows on the second level, two central staircases and two spiral stairwells, with a balcony section that expands forward for that signature “Argentina” vocal. (Hope the sticky-door moment at Friday night’s premiere is fixed; could have prevented Evita from making a grand entrance).

Karen G. Wolfe’s costumes capture the tone of the ’40s with an especially stunning bejeweled white gown for Evita’s iconic arms-up instance, and Friston S. Ho‘okano’s hair and makeup creativity deserves kudos. Stephen Clear’s lighting was spot-on with nary a glitch, coupled with Cameron Olson’s crisp, satisfying sound direction.