It may not be Verdi’s most tuneful or dramatically coherent tragedy, even though the great man comprehensively rewrote the piece 24 years after its unsuccessful 1857 premiere. But Simon Boccanegra is extraordinary in one other respect: it surely contains the most protracted death scene in all opera.

The tormented Boccanegra, a Doge with a dodgy past (but don’t they all have one?), is poisoned by his embittered henchman Paolo (think of Iago without the jokes) halfway through Act II. But he still manages to stagger through to the end of Act III, by which time he has buried the hatchet with his old enemy Fiesco, sent Paolo to the scaffold, singlehandedly stopped a revolution, made up with his long-lost daughter Amelia and anointed her boyfriend Gabriele as the next Doge. Not bad for a bloke with half a pint of hemlock swishing round his innards.

Watching Lucio Gallo in the title role, squeezing every last melodramatic sob and gasp out of this uniquely morbid sequence, is almost worth the price of a ticket in itself. I have reservations about Gallo’s control of intonation, particularly when he pushes his tone on high notes. But it would take a stonier-hearted observer than me not to be gripped by his acting, which makes Peter O’Toole’s Macbeth seem in retrospect like a model of restraint.

It is two other stunning performances, however, that steal the vocal honours in this Royal Opera revival. One is the Fiesco of Ferruccio Furlanetto, who wasn’t even supposed to be in the cast. Is there another Verdi bass in the world who conveys such gravitas, anguish, menace and nobility in such magnificently sepulchral timbres? His King Philip in next month’s Don Carlo at Covent Garden is eagerly awaited.

The other is the German soprano Anja Harteros, who makes a hugely favourable impression in her Royal Opera debut as Amelia. She’s not the most demonstrative actress, but her voice has that priceless Rolls-Royce mixture of power and purr. She is well partnered, too, by the lively American tenor Marcus Haddock as Gabriele. Marco Vratogna contributes a snarling if slightly underpowered Paolo.

Ian Judge’s 1997 production (which now uses the 1881 version of the piece, rather than the 1857) is cruelly oppressed by John Gunter’s sets: massive, melancholy columns and doorways, set askew in swirling murk and a symbolically shattered picture frame.

Despite that, the staging is an admirable attempt to delineate the Machiavellian machinations of 14th-century Genoese politics, particularly through some telling, tableaux-style use of the chorus. And although John Eliot Gardiner takes a little while to ignite passions in the pit – and tends to make some of Verdi’s orchestration sound a little too polite and British – there’s plenty of stylish playing to enjoy too.

Box office: 0207-304 4000

Explore Stage

• Theatre

• Comedy

• Opera

• Dance

Editor's choice

• The top 10 fan versus band scuffles
• Mamma Mia! The first review
• Times critics' 20 best films for kids