New York ? The sign covered by a SOLD OUT notice in front of the Metropolitan Opera House advertised Verdi’s “Rigoletto,” but a better name for the show onstage would have been “Gilda and the Duke.”

Opera’s newest glamour couple, soprano Anna Netrebko and tenor Rolando Villazon made their first joint appearance with the company Saturday night and transformed a routine revival into one of the season’s sensations.

Both are young (he’s 33, she’s 34), wildly attractive, gifted singers and, perhaps most important, brimming with charisma and confidence. Though Verdi gives them only one scene together, their love duet, embellished with some rarely heard unaccompanied harmonizing, sent enough sparks flying that it’s a wonder the ushers didn’t run for the fire extinguishers.

It’s a scene in which the libertine Duke of Mantua, disguised as a poor student, has come to woo Gilda, who unbeknownst to him is the daughter of his hunchbacked court jester, Rigoletto. After the Duke seduces her, the opera moves swiftly to its tragic conclusion: Rigoletto hires an assassin to kill him, but Gilda, hopelessly in love, substitutes herself for the intended victim.

Netrebko, a Russian who made her Met debut in Prokofiev’s “War and Peace” in 2002, has a pure lyric voice that reaches easily above high C and is strong enough to cut through the full orchestra. Technically, she seems to have it all – excellent breath control, an ability to modulate her volume down to a lovely pianissimo and great sensitivity to phrasing. Her one misstep of the night was a flat high note at the end of Act II.

Fine as Netrebko was, Villazon was even better.

The Mexican tenor, whose Met debut came two seasons ago in Verdi’s “La Traviata,” has a full-bodied voice, compact and tightly wound, and he uses it fearlessly, with ringing high C’s at the climax of the familiar “La donna e mobile.” Like Netrebko, he also can scale back the volume, caress a phrase and spin out a long line.

Moreover, he turns what can seem a cardboard villain into a three-dimensional character, oozing charm and arrogance in equal measure. This is a Duke who cannot keep his hands or his lips off any woman he desires and has the unbridled power to get away with it. One gesture in Act I tells you all you need to know about his vanity: While listening with growing impatience to a denunciation by Monterone, a nobleman whose daughter the Duke has seduced, he idly lifts one hand to examine his manicure.

The Met – like Salzburg, Los Angeles, and other houses – knows it has found marketing magic with Netrebko and Villazon and will try to make the most of it in coming seasons. They sing more performances of “Rigoletto” into February, and then she returns in March and April in a new production of Donizetti’s comic “Don Pasquale.” They’re due to be back separately next season – he in Puccini’s “La Boheme,” she in Bellini’s “I Puritani.” Then in 2007-08 they will be paired again as the star-crossed lovers in Gounod’s “Romeo et Juliette.”