Troilus and Cressida, Royal Festival Hall, London

Had Larry directed, might Walton's Troilus and Cressida have been hailed as another Peter Grimes? Olivier, teasing out plans for a new Romeo and Juliet film (never realised) with a score by Walton, might have transformed Troilus's Covent Garden premiere in December 1954 into a visual tour-de-force. In the event, Sir Laurence was busy elsewhere and the critics griped – as they did (surprisingly, given its Puccinian potential) at La Scala a year later.

Troilus needed another champion. Richard Hickox, who conducted the splendid Opera North 1990s staging, and the Philharmonia Orchestra have flown the flag, and triumphed.

The Philharmonia, plus half a dozen punchy soloists, confirm the opera to be not so much an old warhorse as everything one might expect of Walton: electrically charged, vividly coloured, as noble and touching as Henry V, and above all, passionate. The only regal pomp is a nasty march for the Greek grandees, whom a little Berliozian swagger nicely pastiches. The sudden storm is terrifying.

Cressida (Janice Watson, a stiffish Caryatid but as gorgeous-voiced as a Juliet) is a huge role – Walton had Schwarzkopf in mind – with operatic scenas to rival Britten's Phaedra. Walton rescored it for Janet Baker; Lady Walton has now restored the original, though the bossy mezzo Evadne (Jean Rigby) still mirrors Cressida a little too closely.

Hickox's Troilus, Bonaventura Bottone, supplies not just wonderful top notes but a hotheadish youthful tone to outdo any Stratford young puppy.

The plum role is Pandarus. Christopher Hassall's libretto (Hassall, Ivor Novello's wordsmith, was the Tim Rice of his day) based on Chaucer and Boccaccio rather than Shakespeare, is less florid than I feared. His Pandarus, embroidered by the wonderfully involving Nigel Robson ("A delicate supper: quails, figs, wine, a friend or two"), is a hoot. Pears sang it initially, and Walton out-Brittened Britten, writing Pandarus slimy, Quintian glissandi before The Turn of the Screw had even hit the boards.

Roderick Williams delivered a commanding Diomede (shades of Justice Swallow) and Philadelphia-trained Eric Owens a magnificent bass Calkas. With Walton's glorious feel for aria – he aspired to a kind of Italian bel canto – the opera flopped, like Gloriana, from being slotted into the wrong categories. Schreker, its obvious post-Wagnerian forerunner, was unknown; it foregoes strict Bergian structuring; and its Greek context (like Britten's Tudor one) seems to have shackled it. Arguably, it has less in common with King Priam (still in the melting pot) than The Midsummer Marriage.

Indeed, twice Walton lurches into a virtual slow blues for Cressida, to wondrous effect. Just once (in Act I), Hickox clumsily outbalanced her. Dark woodwind stole the day (notably Act 3 – Bohème meets Tristan), but the Philharmonia strings (not least violas) were divine too.