Paula Vogel’s Mother Play: a play in five evictions is a superlative piece of theatre and it demonstrates unambiguously that Sigrid Thornton is one of the great ladies of the Australian stage and screen. It’s difficult to imagine anyone (including the Broadway original Jessica Lange) playing the role of the mother, Phyllis, with two gay children, and giving the role greater dazzle and authority.

There is a long scene at the midway point of the play in which – without benefit of dialogue – she comes home, takes off one of her many blonde wigs – makes dinner and can’t settle to any TV show. Then it ends unpredictably and we’re won over though what it testifies to is the reality of the madness that afflicts her and which she assaults the world with. The effect is searingly intense – it testifies to Sigrid Thornton’s power as an actress and it is utterly riveting as it articulates the ravaged horror at the heart of things in Phyllis’ conception of the world and what comes through is an ability to convey the unspeakable and Thornton does this wordlessly and with all the achieved stillness you could wish for.

It’s understandable that at other moments of the characterisation – in particular with the sweeping dramatic self-possession – things can get a bit rushed. But in this single moment of silent transition in the middle of a crucial and suggestive sequence what Sigrid Thornton does manage is remarkable, tacit and heart-breaking.

The play in its various segments runs from the late-1960s to the present. Through all the gallivanting Sigrid Thornton looks great, she swaggers in her suits, but the play is lit with spectres and nightmares of middle-class poverty. The marriage has broken up and Ash Flanders is fourteen and Yael Stone is twelve – so the kids are allowed to choose which of their Washington, DC parents they want to live with. Yael Stone in fact chooses her brother who thinks that their mother needs looking after, thus leaving Sigrid Thornton with the future monsters of a sexuality she can no more understand than a world where men are sexual gluttons. Or where the mother she’s addicted to talking to on the phone suddenly drops dead.

In this majestic performance Sigrid Thornton captures the cold brittle peformative aspect of Phyllis – the stage queen who dances and prances with such manic and self-involved energy – without ever losing a sense of the suffering beneath the glassy actor’s dream of sovereignty. Great tragediennes have managed this paradox less well – and with less vertiginous grace – than Thornton. This is manifestly one of the performances of this year or any year.

Anyone who thinks Sigrid Thornton is simply a star from a different constellation should think again. Her motherhood is a state of grief from which there is no return. The multiple wigs are like webs of delirium and when we see her in her last moments shorn in her decline to a dim quivering shadow of herself the effect created is one of awe.

The rest of Lee Lewis’ production is not quite at this level. Sigrid Thornton’s performance drips with style and the transcendence of style. But in the characterisation of a great star who shows not the faintest hesitation to appear ugly and cruel the visual aspects of the production could be a bit more sumptuous and symbolically edged. Christina Smith’s costumes – with the cavalcades of Thornton’s wigs and suits are great, in fact all of the costumes are, and in a play like this which moves across time they work as true insignia – but the set is a bit ordinary and this is not justified as a way of conjuring up the penny-pinching that comes with being financially up against it.

And this is quite apart from the absurdly magnified cockroach which looks a bit like the objective correlative of the production’s incertitude.

By the same token Mother Play is a piece that can encompass death and desolation and do so with a lightning brilliance of effect. It’s Sigrid Thornton’s show and she brings to it the full spectrum of her unrelenting wintry coldness and she does so without diminishing the outrage and pain and the towering representation of suffering which is depicted with such power and such poignancy.

Yael Stone does well as the lesbian daughter: she’s spry, ironic, believable and sharp-edged. Ash Flanders as her elder brother starts a bit less steadily but grows in the role. An audience who goes to Mother Play is liable to be confronted with a dazzling and beautiful animation of maternal glory that issues – very powerfully, plangently – into a comprehensive representation of pain, madness and death. If that sounds dispiriting it’s worth remembering that the power of the representation moves us like magic. Aristotle was not wrong about compassion and appal: the effect is tragic.

Mother Play is not a comprehensive image of homosexuality like Angels in America with its range of characters and it lacks the interpersonal complexity of August: Osage County but it is a big show with spectacular effects.

Sigrid Thornton was a pretty dazzling Blanche in Streetcar for Kate Cherry at Black Swan in Perth back in 2014 – more consistently nuanced and psychologically coherent than Cate Blanchett’s for the STC. And Mother Play shows the influence of Tennessee Williams. Is Sigrid Thornton now ready for some of the older women roles in his work? She could, for instance, bring her ice and fire to the role of the mother in The Glass Menagerie. She could play the Ava Gardner part – originally done on Broadway by Bette Davis – in The Night of the Iguana. Or indeed the mother in Suddenly Last Summer. You see glimpses of each of them in Mother Play because of the range of moods and horrors which are conjured up.

We forget that the other side of the sweet Sigrid we saw in SeaChange is the very cool customer of Face to Face and Little Oberon. She’s looking like a goddess in Mother Play – icy, implacable and awful – but with a perpetually broken heart.

Mother Play is the grandest kind of theatre and its grandeur derives from the power with which an actor of the first rank is willing to risk everything as she displays the very idiom of her art as a form of desperation and terror.

Mother Play, by the Melbourne Theatre Company, is on at the Sumner Theatre until 2 August.