The venue was the Grand Palais, a smallish salon, blacked out and dimly lit, with rows of wooden benches. Invitations were scarce, perhaps because the designer had invited so many other designers to attend: , , , , Peter Dundas and friends Kate Moss, Anita Pallenberg, Alison Mosshart, Sky Ferreira, Pixie Geldof… and possibly many more; it really was a dim room.

To say expectations were high for Hedi Slimane’s debut ready-to-wear collection – now to be referred to as ‘Saint Laurent’, we were told via bulletin email from the house, and the new logo ‘Saint Laurent Paris’ not to be written about or indeed spoken of, and all picture captions to be labelled ‘Hedi Slimane for Yves Saint Laurent’ – would be a gross understatement.

This was his first womenswear collection ever - having designed only menswear up until now, Dior Homme (famously worn by many women) and before that YSL Rive Gauche Pour Homme, chosen to do so by himself.

Building the atmosphere to that of a knife edge, great panels of the blackened ceiling slowly lifted back, stadium spotlights swivelled, huge speakers descended through the roof (blasting out ‘Junior Kimbrough, edited by Daft Punk’). Pause. Long, long pause. And what do you think stepped out? Minimalism? Pure, sleek, spare, austere minimalism? Isn’t that what we all associate with Hedi Slimane?

If you Google ‘Yves Saint Laurent 1970s’ – as I did – you’ll see it all there. Great wide-brimmed hats, sweeping long romantic dresses clasped at the waist with wide belts, lace-front safari shirts, hip-riding floor-sweeping skirts, a leopard kaftan, pussy-bows at the neck, tuxedo jackets and blazers, long capes, voluminous sheer sleeved blouses…

It was a shock. A shock because it was so unexpectedly reverential and retro. But it was brilliant. Brilliant in the way it was styled, brilliant in the way it mixed in rock ‘n’ roll – a sequined jacket here, a long gold fringed skirt there, a massive black and white chevron striped feathered cape – and brilliant in its absolute authority and confidence of a focused single theme.

It also put paid to the idea, long held, that the fashion world was about to be dominated by two purists at the two most sacred fashion houses in Paris – Hedi at Yves Saint Laurent versus Raf Simons at Dior. The question was, who would out-minimalise the other. But, if this collection is anything to go by, that might never happen.

This Saint Laurent woman is a sexy, louche, strung-out thing dripping in cool (picture Kate Moss or Anita Pallenberg in anything from this collection) whereas Diorwoman is as subtle, refined and chic as it is possible to be.

The bottom line here – when you can see Kate Moss mentally ordering everything in her head – is that it will sell. And sell. And sell. And as for the high street…

See Kate Moss and Salma Hayak from row at Saint Laurent

Check back shortly for every look from the collection