Swan Lake, Guangdong Acrobatic Troupe of China, London Coliseum

What you see in the picture is the money shot, and yes, it's a miracle that you won't fully believe, even as you watch it.

But there are plenty of other belief-defying miracles in the Guangdong Acrobats’ version of Swan Lake - just don’t make the mistake of calling it a ballet, especially not in earshot of the haute-couture Mariinsky Ballet, currently up the road at Covent Garden. This is pure freaky acrobatic theatre, in a tradition that goes back two millennia in China, and driven by an insatiable ambition to outreach the possible which could only come out of so ancient and serious a tradition.

The schooling, discipline and bravery that must be involved to create the stunts and entertainments on show here can hardly be imagined by indolent Brits: according to the programme book, the performers on the Chinese poles habitually turn 1,440 somersaults a day practising their hair-raising feat flying from the top of one 30ft pole to another and landing upside-down clinging only with their knees.

That this is knife-edge stuff each night - never mind that this show has been going since 2006 - was evident last night in the proliferation of little mishaps through many acts. Jugglers dropped things, chaps on the mesmerisingly spinning German wheels collided, one of the roller-skating Swangirls crashed to the floor in a pile of undignified feathers and tulle around which 23 other roller-skating Swans had very carefully to not fall over while gliding to their next formation. And one's heart was in one's mouth - was last night an inauspicious date? Would any of this bad luck rub off on the central couple and their death-defying balletic acrobatics?

For if any world-touring show boiled down to a single pair of people, this one does. Wei Baohua, a muscleman in tights, and his bird-boned wife, Wu Zhengdan, are the be-all and end-all of the Guangdong Swan Lake, performing an act apparently without parallel, and presumably therefore without understudies. This week Wu has delicately balanced on pointe in splits, gravityless, on her husband’s head already five times at the London Coliseum, with another three to go this weekend. She will do so again next week in Cardiff, and the week after in Birmingham.

The entire Swan Lake show evolved (as they do) from a little act she and her husband cooked up in 2004 entitled unpretentiously Oriental Swan-Ballet on Top of Head, and out of this golden nugget has emerged a spectacular production featuring a wide range of China’s famed acrobatics, staged to Tchaikovsky’s ballet music, and roughly in sync with its story, but essentially focused on displaying a company derring-do and legerdemain of wonderful entertainment value and deftness.

A chap juggles unbelievably nimbly with hats, while a large corps de ballet(ique) of girls in desirable red ruffled dresses and red pointe shoes juggle complementary fusillades of hats behind him. A sturdy girl in a snake costume performs simply incredible contortions with utmost dignity, even when her head seems to be emerging from where no head should be and a chap is handstanding on her elbows, rather than courteously helping to unknot her, as a gent ought. (Tan Wanxia and partner pictured below.)

The balancing acts are ingeniously engineered feats of teamwork - a woman upends herself while clutching five right feet raised high in the air by a circle of her mates all helping each other to stand on one leg. Evidently one person balancing on another's solidly anchored points is only for ninnies like the Cirque du Soleil; when it’s about stacking unstable layerings of non-load-bearing parts of all sorts of people, with some bold little girl stuck into the top of the pile on one hand like a cocktail umbrella, that could only be a fiendish Chinese invention.

As, surely, is some of the humour, so unlikely that it’s surreally apt. The Spanish dance in Act III is performed by women on pointe partnered by men on unicycles (I want that fixed permanently in the echt text). The Cygnets are frog men hopping entirely on their hands. And the very idea of the Oriental Swan-Ballet on Top of Head could never have been born in the sphere of classical ballet itself, but only in a nation so earnestly at home with the virtually impossible that the unthinkable has to be the next step. There are apparently 25,000 acrobats performing in 200 professional troupes in China, mostly graduates, like Wei and Wu, of national gymnastics teams. After the Beijing Olympics, where China cleaned up most of the gymnastics medals, one assumes more will be scooting to audition for Guangdong and other troupes, with more and more unfeasible stunts on offer.

Do go. You will never see such an impossible sight, certainly not in the regulations-hamstrung West. He is 40 now, and she is 31. Their choreographer does insist that they perform sequences of arm-flapping ballet-lite, but there is plenty else to make your eyes water. It would be very company-minded of them to continue doing their speciality act year upon year until he is too stout and tired, rather than until they both got titanically bored of doing what for them is a job they evidently must perform, with boneless, oiled efficiency, without the smallest variation each night. I can't guess at the resilience of mind required through, almost certainly, dozens of falls and injuries, dozens of times of getting back up there, holding the nerve, and doing it with more and more minutely exact co-ordination next time. Regardless of taste, it’s one of the most dauntless achievements I’ve ever seen in the theatre, and without doubt the most jaw-dropping.

• Acrobatic Swan Lake is at the London Coliseum till tomorrow; then tours to the Wales Millennium Centre, Cardiff 18-20 August, and Birmingham Hippodrome 23-27 August

Watch the official production trailer for the Guangdong Acrobatic Swan Lake