Kate Middleton is teaming up with a tennis legend in support of a great cause that's near to her heart. According to People, the Duchess of Cambridge will join 20-time Grand slam winner Roger Federer on the court in London to promote fundraising and awareness for Action for Children and the LTA Foundation, which both support disadvantaged and vulnerable children.

The day of tennis will give children from East London ages 8 to 15 the incredible opportunity to play alongside Federer. The goal is to encourage young people from all different backgrounds to become involved in the sport and reap its mental and physical health benefits. The event will be followed by a charity Open Practice Day on September 23rd for the Laver Cup, which is an indoor hard court men's tournament that sees players from Team Europe and Team World go head to head. Fans will watch Federer and stars from Team Europe and Team World prepare for the tournament. All proceeds from ticket sales will go to Action for Children and the LTA Foundation.

Middleton is a vocal fan of tennis and even has a court at her home at Anmer Hall in Norfolk. In fact, another tennis champ Rod Laver revealed that Prince William can never beat his wife at her favorite sport. "They play tennis against each other," Laver said. "William told me he couldn't beat her." The royal couple also takes their children to a club in London for regular tennis lessons and are regulars at the Wimbledon tennis championships in London every summer.