When Plácido Domingo collapsed, dead, at the Royal Albert Hall at the end of Covent Garden’s semi-staged Simon Boccanegra there were concerned faces on the stage. It was a convincing swoon and maybe the demised Doge stayed prone longer than expected. Perhaps he was exhausted (he had every right to be) but when he eventually rose – and Tony Pappano’s concerned features relaxed into joy and relief – close on 6000 people rose with him in a spontaneous standing ovation that brought to a close one of the great Prom experiences.

By rights you would think there should be something lacking in a concert or semi-staged performance of an opera. After all, it’s not the real thing, is it? That wasn’t the impression here – helped by the fact that the principals were costumed and acting even though the chorus was positioned as a choir and in evening dress. After the disappointment of the performance at Covent Garden, where the Fiesco, Ferruccio Furlanetto, who had lost his voice suddenly, acted out the role while John Tomlinson sung the role from the wings, the Prom caught fire. Furlanetto had found his voice again – what a fine resonant bass he is – and there wasn’t a weak link among the principals.

Joseph Calleja just gets better and better. The tenor role (Gabriele Adorno) is not the most interesting in this supreme opera of political intrigue but Calleja came close to stealing the show – his “Cielo pietoso, rendila” was mellifluous and moving – although the plaudits have to be shared. Marina Poplavskaya was a determined Amelia Grimaldi (Maria Boccanegra) and during her scenes – whether with Calleja or Domingo or both – one lost track of being in the concert hall rather than the opera house. This was opera at its finest.

Furlanetto’s Fiesco is to be treasured. A patrician, perceived initially as one of the villains of the piece, Fiesco has integrity and nobility and Furlanetto conveyed this both in his movements and vocally.

Pappano coaxed an exceptional performance from his house orchestra and chorus – he has a special feel for his Verdi, witness his recent Requiem – but the final plaudits have to be reserved for Domingo. Perhaps he saved his best for last. Whatever the case, he treated a rapt, packed Proms audience to one of the great portrayals of one of opera’s more interesting heroes. The timbre of the voice does not have that baritonal bite but this was a lived-in and very finely sung Doge, believable in its own right. One was privileged indeed to have been there.