Not even jammed scenery, and a five-minute hold-up, could put the National’s first night audience off the scent of a major triumph for playwright Howard Barker (making, absurdly, his NT debut), director Tom Cairns, designer Hildegard Bechtler or Fiona Shaw.

Shaw plays Galactica, a fictional 16th century Venetian painter charged with celebrating the Battle of Lepanto on a huge canvas but producing instead the equivalent of Picasso’s Guernica, “a great waterfall of flesh” with horror to the fore and victorious sea captains to the rear.

Not that we see the painting, though we do meet one or two of the characters in it, notably a man with a boiling bowel and a bolt in his brain, and a Turkish prisoner with the reflex hots for Galactica’s daughter. This was, after all, originally, an award-winning radio play starring Glenda Jackson, who also led the fine Almeida stage version in 1990.

Cairns and Shaw now make something even more epic and lucidly Brechtian – Galileo comes to mind – of Galactica’s clash with her sponsors, the supercilious Doge with a fetish for art (Tim McInnerny giving the perfect performance) and the prosecuting Cardinal (William Chubb equally good).

The Doge, as if encapsulating NT artistic policy, resoundingly declares that “we embrace all, and show our greater majesty”; this illustrates the nub of Galactica’s dilemma and Barker’s tussle with his own status.

Popular art is a kind of defeat, whereas critical acclaim – personified in Phoebe Nicholls’s swanky, well-dressed and absolute art critic, who believes a painting is retrievable even when the artist is lost – kills the creative instinct in acts of explanation and appropriation.

The richness of Barker’s play lies in the energising of this metaphor, and Shaw’s breast-baring journey through it, from frustration with the commission, to despair at her lover Carpeta’s (Jamie Ballard) rivalry and rational suggestions, and her sensual deprivations in prison, conjures a soul in torment, a trembling portrait of displaced feminist modernity.

Bechtler’s brilliant setting of great slab-like mobile squares resembles a room full of giant Mark Rothko paintings, which change colour from oatmeal to grey to murky red under the lighting of Peter Mumford, with an evocative, muffled soundtrack by Ben and Max Ringham.

This is one of the best uses of the difficult Lyttelton stage I’ve seen. More importantly, although Barker will despise me for saying it, and for being so patronising, the occasion marks a significant rehabilitation of the playwright in our major theatres.

It is many years since there was an unforgettable RSC season of his work (playing in The Pit while Les Misérables was on the Barbican main stage). It’s high time the National followed suit, and quickly, too. There’s a pugnacious tone, and a liberated style, about Barker at his best that is unlike anything else on our stages today. And that is because he doesn’t write plays. He writes theatre. The audience is hungry.