Out of the outrage comes gold: Vivienne Westwood has wowed Paris again, but this time has won more than just applause

'We'll sell it, there's a million ideas there,' said Gene Pressman, chief mandarin of Barney's New York, probably the most important fashion store in the world. Sales to German shops were up 10 times on last year by close of business on Wednesday night.

The press declared her collection a triumph, the designer Azzedine Alaa was speechless, while Jean Paul Gaultier was ranting in ecstasy. Supermodels in bloody battle with American designers over fees are said to have worked for Vivienne Westwood in return for clothes. By Thursday, Marie Claire had done a cover shoot with the clothes and Steven Meisel had snapped them for US Vogue. She's seen all that before: a wacky outfit on a glossy cover is one thing, it is something quite different on a hanger in a store.

This week's Westwood show was staged at the opulent Grand Hotel, where Christian Dior couture shows are always held. It cost a lot, as much as her company could possibly afford, but it should be the beginning of a new story - the moment when she stops being just a wacky source of free ideas, the moment when she moves from succs d'estime to success. Westwood seems this time as never before to have pulled off the fiendishly difficult balancing act between being freely creative and highly commercial. The buyers, obsessed with money in these tough times, spotted highly saleable clothes in Westwood's saucy romp of a show. Flared trousers with a 12ft train on each leg will be tricky, but rose-printed satin separates, abbreviated skirts, what can only be described as sexy knitwear and Henley-striped blazers on an acid trip should sell.

She has long been recognised for her contribution to fashion - John Fairchild, publisher of the mighty US magazine Women's Wear Daily, has named her, along with Yves Saint Laurent and Giorgio Armani, as one of the greatest creators of our times. But while Saint Laurent, Valentino, Calvin Klein, Ralph Lauren et al have wealth enough for Learjets, yachts and beach-front estates in Jamaica, Vivienne Westwood, mother of two, lives in a south London flat and rides a bicycle.

Her business used to be chaotic, run from a catacomb of freezing rooms in Camden Town by her son Joseph Corre. He is no longer with the company and is said to be opening an up-market sex shop. Meanwhile, she is now rehoused in decent premises. The formula: British small-scale production and Italian mass manufacturing.

She has had her false commercial dawns, rip-offs and deals that did not materialise. But this time it all looks a lot more solid. Littlewoods' catalogue will feature a Westwood collection next summer and the French catalogue Trois Suisse has also commissioned Westwood.

There's a deal with the bag maker Braccialini; the shoe manufacturer Charles Jourdan; Swatch watches (with Westwood's limited-edition orb watch now changing hands for hundreds of pounds); a licensing deal with the Japanese conglomerate Itochu, which should make the business big there; plus ongoing perfume plans with Trucocco. Liberty, the London store, now offers exclusive Westwood wedding dresses; and a Westwood book, to be published by Thames & Hudson and featuring the work of leading photographers, is due out next year.

Vivienne Westwood, a greengrocer's daughter born in Tintwistle, Derbyshire, in 1941, is at her peak. Yves Saint Laurent, born in Oran, Algeria, in 1936, is clearly in his magnificent career's twilight. The company he founded with Pierre Berg is now owned by the petroleum giant Elf Sanofi. Saint Laurent's design contract expires in 2001, but the whisper in Paris is that he would happily leave beforehand.

Despite Berg's protestations in the past that he would close the YSL couture house if Yves retired, it is no longer solely his and Yves' to close. How glorious it would be if instead they handed the keys to Vivienne Westwood.