When H&M's Oxford Circus store threw open its doors at 9am, it was promptly swamped by a wave of fashion-savvy bargain hunters desperate to get their hands on an original Stella McCartney - for a fraction of its normal price.
They had travelled from as far afield as Oxford to join a queue that began forming at 6.30am outside the central London shop and swept through to clear the rails within an hour.
Carlotta Gherzi, 25, a designer, said: "When I went into the store I was carried along with the crowd. Things were being thrown on the floor and people were grabbing what they could.
"It's great to get an original piece of clothing designed by Stella McCartney while she is still working under her own name. It gives you something to look back on in 10 years' time.
Megan Browberg, 27, a personal assistant from Shoreditch, east London, spent around £240 on seven jackets and tops.
She said: "I got an early lunch break and had to buy a lot of stuff for the other girls in the office who couldn't get to the stores.
"It was insane inside the shop - stands were shaking and people were running in.
"Stella's done brilliantly. There was nothing over £100 - which was fantastic. When big-name designers do these collections, there is an opportunity for all size ranges. Doing a high-street range is really a sign of a great designer."
Some calculated shoppers even turned up with lists after scanning the store's website. Popular buys included McCartney's trademark skinny jeans for £39.99, sweater dresses for under £60 and a tuxedo jacket for £59.99.
Prices for the collection range from £7.99 for a keyring with the letters STELLA attached in a light pink plastic to £39.99 for grey and blue denim jackets. Each item had attached a personal note, allegedly written by the designer, stating: "Take me home, put me on and feel good! x stella".
Mee-Ling Skeffington, 30, an assistant theatre producer from east London, spent £125 on clothes from the collection.
She said: "I knew what to expect before arriving at the store as I had checked it out on the web. It is definitely H&M quality, but in Stella style. The prices are ridiculous for the clothes designed by Stella."
McCartney said yesterday: "My one-off collection for H&M is pretty much like the pieces I do for my own signature collection."
The frantic scenes in the capital were repeated in 25 stores across the country, from Edinburgh to Essex, reflecting the inexorable rise to the top of the fashion tree of a chain that began life as a dress shop in Stockholm in 1947.
The company now sells more than 500 million items of clothing a year, and flagship stores such as the shop in Paris need a daily delivery of three lorryloads of garments to satisfy demand.
McCartney is not the first designer to create a collection for the brand, following in the footsteps of the German designer Karl Lagerfeld.
His collection also sold out within hours of going on sale in the chain's stores last year, earning him plaudits. But the relationship soured when he complained vociferously after seeing his clothes on sale in a size 16.
He said at the time: "What I created was fashion for slim, slender people. That was the original idea."
The store is no doubt hoping for a smoother run with McCartney, whose haute couture designs have already been praised for flattering the British figure.
Plans for the launch did encounter a hitch in September when the store joined Burberry and decided to drop McCartney's friend Kate Moss as the face of the collection after the model was accused of taking cocaine.
But yesterday, shoppers were not put off by the connection.
Rona Gearey, 59, who travelled from Henley, Oxfordshire, with Vicky Kempster, 26, said: "I wasn't impressed when Kate Moss was dropped. I did think it was a bit unfair and I thought twice about coming to the store - but it is Stella McCartney."
The collection was unveiled in around 400 H&M stores in 22 countries worldwide including seven in London.