He calls it a farewell tour, and if it is then it’s astonishing to think we might have seen the last of Barry Humphries on stage. He has dominated the nation and the world like no other comedian, like no other actor in any medium. How extraordinary it is that some luvvie-ish boy from Melbourne Grammar in the mid-Fifties could take the crumpled suburban idioms of his native Melbourne and turn them into a thing of magic and mayhem so that Edna became an avenging deity of Australian femininity (as black and berserk as a land of misogyny and matriarchy could muster) and Sandy Stone could bleat his mute little circumlocutions and clichés like the voice of a nominal maleness nothing in his society would uphold. At the level of conception, of articulate verbal invention and then — sweepingly — in the mastery of his performances as these two, as the yobbo Les Patterson (Humphries’ bouquet to Sydney) and as a whole line of other, now vanished, comical ghosts, he deserves the title of genius we have given him these many years. He is the greatest performer in Australian history and the fact that he is also that almost archaic thing, a female impersonator, as well as that streetwise thing, a stand-up comedian, seems like a cartoon of the truth because he has contrived it so that his creations should seem more real than he does.

In any case his farewell show Eat Pray Laugh! is a thing of such zest and delight that it comes across with its production by Simon Phillips in Hollywood cartoon colours and with dancing young lovelies baring skin and adorning it with Indian finery, a bit like a technicolour coda to the world of Barry Humphries. But there’s no doubting the rampaging reality of his personas of Les and Edna, even if the dark-suited beautifully-spoken gent who comes on at the end, looking like his famous self-description (‘I am not an Australian, I am a Victorian’), the very model of the Melburnian Anglophile, is in his way — and with all his glories seeming for a second like the transience of the mundane world he abhors and adores — even more moving than the afterlife of Sandy Stone.

We begin with Les Patterson, not only spitting but loudly and hideously shitting as well in the outdoor toilet that abuts his barbecue. He sings merrily about cuisine and bills himself as Australia’s answer to Nigella Lawson. He finds a hapless couple in the front stalls — he a middle-aged Melbourne Grammar boy, no less — who are conscripted into helping him with the rissoles while handing him extra sheets of toilet paper. There are plenty of jokes about Asians and Aboriginals and gays, which kept the first-night audience laughing at yesterday’s heroics, and there’s a culminating hilarious gag about Les’s daughter’s boyfriend’s fingers and where they’ve been.

Les Patterson has always been Barry Humphries’ valentine to the great Australian crassness, and with a lightning costume change he is replaced be a new character, his brother Gerard, who turns out to be Brother Gerard, a molesting Catholic religious, with an electric ankle bracelet alarm which goes off when he, for instance, sticks his feet in the crotch of a young Asian eye-candy boy who is assisting Les with the garden. Brother G is refined of vowel, bald of head and wears a hideous synthetic version of traditional clerical dress. His family resemblance to Les is by way of teeth.

He is followed by the ghost of Sandy Stone, the figure with whom Humphries, at the zenith of his powers in the late Sixties, when I first saw him, could reduce an audience of young unbelieving cynics to tears with material that might have been written by James Joyce and was delivered with the wan, uncomprehending wonderment of Alec Guinness at his finest.

Well, Sandy Stone is the ghost of his former plangencies, but Humphries can still compel that knife-edge silence when Sandy remembers the daughter with her little bike from Tim the Toyman’s who died, back in the 1930s, as a little girl. 

Sandy is a monument to the white picket fence and privet hedge Australia, with his vistas of Glen Iris as the best of all possible worlds in a world without much possibility, and there are moments watching him when you know this is Barry Humphries’ true face of Australia, the face at the depths of the self, the might have been and always was, compared with whom Les and Edna are the masks for the savage dance when the melancholy clown pretends that life is a comedy.Edna comes on like a goddess of predestination and raps with the audience and her chosen victims with extraordinary elan. She makes a joke about the horse called ‘Blackman’ (whose name is being changed because of fears of suspected racism) and when the audience fails to guffaw or get the joke she remarks that she’s better informed than they are.

Edna is, of course, the second self, the stand-up and supremo. She makes jokes about how it’s no wonder Gina Rinehart needs two seats and she devours the front stall victims.

Randall Marsh, the architect, risked a fate worse than death sitting in the front row, but escaped having only to twiddle his gladdie — which he did with panache.

Edna’s victims on the Melbourne opening night were all older people, and none of them looked liked regular first-nighters. There was a lady from Armidale who was compelled to sing ‘Over the Rainbow’ and everybody’s clothes and taste and intelligence were traduced with queenly malignancy by the great dame. Then the victims, having been lured onto the stage, were sent backstage to return as respectively Cleopatra, Marilyn, Mother Teresa and Amy Winehouse in gladrags that might have been dreamed up for a Simon Phillips musical.

It was Dame Edna at her most sauntering, Barry Humphries at his most relaxed. Edna’s repartee was at its most inspired and deadly. The changes she rang on ‘epiphany’ when the victim in the audience said it meant ‘moment’ drew gasps.

You could watch her forever, and in some sense that’s what we’ve been doing.

The very fizzy, weirdly intense waving and shaking of the gladioli was, why wouldn’t it be, a bit like the end of an era.

We were sitting in the same row as the playwright Joanna Murray-Smith, whose glittering career had been summed up mysteriously as ‘Broadway performer’ in a recent publicity release, and in the row in front of the director, Simon Phillips. Up in the dress there were figures like Geoffrey Rush, the country’s greatest actor, and Bill Henson, its finest photographer. But somehow no one can put on their dancing shoes in the presence of Barry Humphries.

You can only pay tribute and be part of the idiot chorus. When he came on, as himself, at the end, the effect was so quiet, so reserved, so much the apparition of the unknowable reality of the imagination from which it all comes.

Catch him with your children or your children’s children during one of these putative farewell shows so they can say they saw one of the great spirits of the age.

Eat Pray Laugh! is at Her Majesty’s Theatre in Melbourne until 4 August, then tours to Auckland, the Gold Coast, Adelaide and Perth.