La Traviata, Royal Opera House, London

A stellar Violetta steals the show

The five stars belong to Anna Netrebko. Just when you thought that no one could put the dramatic imperative back into Richard Eyre's impassive staging, along she comes with her fabulous technique and volatile temperament to remind us (as if we needed reminding) that stars are born, not made.

This Violetta does not go quietly into that long, dark night. With a consumptive cough every bit as alarming as the fearsome challenges of Verdi's emotive coloratura, her instinctive response is to reach for another glass of vintage champagne. At least, in Act I it is. By Act III, love and humility have made her someone else. And it's the journey there that makes this "fallen woman" special. Netrebko is, in a word, sensational.

We first see her picked out of the darkness, as Verdi's ethereal prelude hazily reflects on her destiny with its premonition of music from the final act. This is the private Violetta – lonely, and alone. But then the lights come up, the party crowd gathers, and she's "on". There is a discernible switch: suddenly Netrebko is vivaciously spinning from one guest to the next, all things to everyone. And then Alfredo arrives in the alluring form of Jonas Kaufmann – and it is clear that this isn't about to be a one-woman show.

In this crucial opening party scene, both these exceptional artists boldly put aside operatic pretence and play their electric first encounter for real. Naturalism is a dangerous game in the cumbersomely high-flown world of opera – but then, so is the nature of their liaison.

So how do they do it? By freezing the moment where their eyes first meet and romancing each other in phrasing that is at once fresh and intimately inflected. Both make seductive, elegant turns in the drinking song; neither sings it as you expect it to be sung – or usually hear it sung. Kaufmann's singing is so relaxed, it's almost horizontal.

But then Violetta is alone again and Netrebko is in business. I don't think I've ever seen the thought processes of this demanding scene, "Ah, fors'e lui", so clearly, so grippingly, conveyed. This is "the method" applied to singing. Where most Violettas are busy contemplating the next tricky roulade, Netrebko is lost in the intoxication of the moment. First, she's using the coloratura flippantly, blithely disbelieving that he might be "the one". Then, like an echo of his palpitating heartbeat, she recalls the music of Alfredo's confession of love, finding breathless in-the-moment shadings for words like "mysterious" and "exalted". On then to the delirious cabaletta – "Sempre libera" – dismissing the notion that she must be forever free by convincing us that she doesn't for a moment believe it. And that, predictably, brings the house down.

Of course, none of this is possible if you don't have the technique to pull it off. Netrebko's strength is not just in the mobility of her voice and the razzle-dazzle of her upper register's big-money notes – no, it's the fullness and beauty of the middle voice that singles her out and makes key moments like the emotional outburst in Act II – "Amami, Alfredo" ("Love me, Alfredo") – properly overwhelming. For once, fullness of heart is truly matched in fullness of sound.

But that moment only works because of what comes before it – and the third member of the "dream team" first cast for this revival is Dmitri Hvorostovsky. His physical reserve on stage is harnessed to good effect here, as the father who cannot see beyond Violetta's reputation to the woman his son truly loves. The role centres on the nobility of sustained legato singing, which is Hvorostovsky's speciality.

In the pit is a true Italian, Maurizio Benini, who fully understands the rhythmic impulse that drives this score. But the evening belongs to Netrebko – and if you didn't know the ending of the opera you might believe in miracles, as the pain ceases and she momentarily rises from her deathbed to rejoice in the knowledge that love conquers all. Especially the Covent Garden audience.

In rep to 14 February (020-7304 4000)