Invitations to the Queen's Jubilee luncheon were only handed out to European royalty, but there was a Kiwi name on everyone's lips at the exclusive soiree - Emilia Wickstead.
Wickstead, 28, from Auckland, was the designer behind the Duchess of Cambridge's elegant, rose-coloured dress.
Photos of the $2500 dress went around the world, and Whitecliffe College of Arts and Design founder Michele Whitecliffe said the publicity was priceless.
"Money can't buy that sort of endorsement. Kate Middleton is the most admired woman in the world right now and Emilia will be riding the wave of success," she said.
"Kate is the personification of elegance. She's tall, she has an amazing figure, she looks amazing. I'm sure Emilia's business will grow enormously."
Fashion commentator and blogger Amber Whitecliffe said the duchess was a perfect fit with Wickstead's brand: "It sends that message of being elegant, sophisticated and glamorous."
Product placement agent Kim Ellet agreed that Wickstead's business would boom - as it had when the Duchess wore a different Wickstead garment on St Patrick's Day in February.
"Anything Kate wears get world-wide attention and tends to sell out the next day. All of a sudden, people will be seeking out that designer. This is huge for her."
The luncheon celebrated 60 years of Queen Elizabeth II's reign.