Lady Gaga opened Philip Treacy's show wearing a flower-inspired hat at London Fashion Week yesterday (16.09.12).

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The singer - who did not perform at the spectacle - stunned onlookers as she took to the catwalk at London's Royal Courts of Justice in a floral-adorned, helmet-style headpiece. She then paid tribute to the hat designer by describing him as the "greatest milliner in the world".

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Gaga watched the rest of the Michael Jackson-inspired show from the front row of the catwalk alongside model Kelly Brook and 'Sex and the City' actress Kim Cattrall.

Treacy used his first show in the capital in more than a decade to pay tribute to the late 'Thriller' singer, and one hat even featured a mini fairground based on the one the musician - who died in June 2009 - used to have at his Neverland ranch.

The milliner - who is well known for his unconventional designs including the "pretzel" hat worn by Princess Beatrice for Prince William and Duchess Catherine's wedding last year - used only black models, such as Jourdon Dunne and Alek Wek, to showcase his latest headgear designs.

Following his show, Philip celebrated his return to the London Fashion Week schedule by attending an after party at The Maddox Club in London, where guests - who included Grace Jones, Dita von Teese and One Direction's Niall Horan - were treated to bespoke cocktails including Ciroc Rocks, consisting of Ciroc, Elderflower and Soda.

Grace - who attended the catwalk show earlier in the day - was one of the last to leave the venue and spent the last hour showing the young models, including Alex, her vast array of dance moves.