They're the new golden couple of opera, and although any romantic linkage between Anna Netrebko and Rolando Villazon is strenuously denied, few at the Barbican last night believed it. Certainly they've worked closely together of late: first in a controversially chic production of La Traviata in Salzburg and more recently in Massenet's Manon in Los Angeles, where, as here, they won all hearts.

As evident as their star quality is the rapport, both musical and physical, as duets from Manon, La Boheme and Tchaikovsky's Iolanta demonstrated. Caresses and embraces help to make their characterisation credible: you could believe these two were swept off their feet by each other. That was some achievement because the programme's bittiness was exacerbated by the constant processing on and off stage by singers and conductor (the competent Emmanuel Villaume).

It was also a programme that played to the new development of Netrebko' s voice. She is now tackling more of the heavier Italianate repertoire (Puccini, for example), as well as Massenet and Gounod ) as befits a successor to Callas and Gheorghiu. It's a darker, richer, more interesting tone than that she deployed in bel canto. She also modulates it adroitly and can convey both breathless excitement as Gounod's pleasure-seeking Juliette or inhabit the sombre, elegiac world of a Rachmaninov lament.

Villazon sustains a secure, ringing tone, less variable and nuanced than Netrebko's but still thrilling. His delivery of Lensky's doomladen aria from Eugene Onegin was sturdily eloquent rather than heartbreaking.

In a playful piece of theatre, the operatic lovers Mimi and Rodolfo strolled offstage arm in arm, at the end of their duet from La Boheme, sending their top Cs spinning back into the auditorium. Encores included Bernstein's Tonight and a fancy-dress Verdi Brindisi, complete with piratical hook.