Kate Middleton made an appearance at Wimbledon and on Snapchat on Thursday afternoon as an excited Serena Williams recorded herself meeting and the Duchess following her victory over Russian Elena Vesnina in the women's semi finals.

Looking totally composed despite having just finished a match, Williams takes a video in selfie mode explaining the camera "OK, so I'm in the 'In Crowd' now, I'm with royalty". The video then pans over to show the tennis star posing with Kate Middleton and Sophie the Countess of Wessex who are smiling but hesitant to be on camera.

serena and kate
Serena Williams beamed alongside Kate MiddletonSnapchat

Thursday was the Duchess's first outing at this year's Lawn Tennis Championships in SW19 as she joined the crowds to see Serena beat Vesnina in a semi-final lasting only 48 minutes which led her into the final of the championship. Williams will face her Australian Open nemesis Angelique Kerber of Germany in Saturday's final.

Serena Williams
Serena Williams breezed past Elena Vesnina to seal the ninth Wimbledon final appearance of her illustrious careerShaun Botterill/Getty Images

Middleton brightened up the court in a recycled vibrant yellow Roksanda shift dress with white panelled inserts on the skirt that she had previously worn during a royal tour to Australia in 2014 with husband Prince William, who said that she 'looked like a banana' in it.

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Kate Middleton was joined by Gill Brook, wife of Wimbledon chairman Phillip Brook in the Royal Box to enjoy the Serena Williams vs Elena Vesnina match at WimbledonGetty

Stepping outside Centre Court the Duchess also met with Wimbledon chief Phillip Brook and chatted to ball boys and girls ahead of the semi-final.