Kate and Sophie pose for video snap with the Queen of Wimbledon after Serena Williams storms into final and declares: 'I'm in the "in crowd" now... I'm with royalty!'

Serena Williams celebrated her Wimbledon semi-final victory today by posting a 9-second Snapchat video of her posing with the Duchess of Cambridge and the Countess of Wessex (left). The video was a royal first and Kate and Sophie beamed with delight as they embraced the World Number One after her straight sets 6-2, 6-0 victory over Russia's Elena Vesnina on Centre Court. Serena posted the video with the caption 'OK so I'm in the "in crowd" now... I'm with royalty.' Earlier Kate and Sophie had enjoyed a friendly catch up in the Royal Box (right) seated next to Philip Brook, chairman of the All England Lawn Tennis Club. Keen tennis fan Kate, 34, also toured the SW19 grounds and met balls boys and girls and former British tennis star Greg Rusedski. She recycled a £900 bright yellow and white colour block dress by Roskanda, which she debuted in 2014 on a visit to the Syndey Opera house.