Puccini's La Rondine (The Swallow) has reached Covent Garden some 85 years late. The work was the nearest the composer came to a flop, yet, as this traditional production by Nicolas Joel demonstrates, it has all the ingredients for success.

What was wrong originally was the timing. It was commissioned by the Vienna Karltheater in 1913, with Lehar operettas as the likely model. But Puccini found his plans tangled up in the first world war, and the piece eventually received its premiere in Monte Carlo in 1917. Its mixture of lightness and poignancy was alien to the mood of the time, and it was quickly written off.

Yet Puccini took endless trouble with the libretto, which offers a cunning mixture of La Traviata (young innocent infatuated with kept woman) and Die Fledermaus (big central party scene with maid appearing in mistress's clothes). Previously it has seemed problematic that the exuberant high-jinks of the second act are followed by Magda's renunciation of her young lover, Ruggero. That final act can feel like a dying fall. It is the achievement of this Covent Garden staging that the sweet-sour close is so effective.

Casting is vital, and here Angela Gheorghiu and Roberto Alagna have found a vehicle made for them. Gheorghiu gives an inspired reading of the letter from Ruggero's mother, masterfully conveying the heart-tugging conflict of Magda as she realises the impossibility of marrying her young lover. On the final curtain she stands ramrod stiff, looking straight out at the audience, preparing to face her old life again.

Gheorghiu is equally good in act one as a mature courtesan, her voice gloriously full and rich. As Ruggero, Alagna charmingly conveys eager innocence. Gianluigi Gelmetti's sympathetic conducting brings out the score's striking melodic motifs, each one relating to a recurrent theme, not least that of the swallow flying away.

There is fine work from the supporting cast, even Cinzia Forte, who overacts outrageously as Magda's maid, Lisette. The second tenor role of Prunier is often feebly cast, so as not to embarrass the principle tenor singing Ruggero. Here the part is taken by Charles Workman, who is characterful and vocally strong. He provides a clear contrast with Alagna, who is never in danger of being outshone.

· In rep until May 22. Box office: 020-7304 4000.