William and Kate in Wimbledon royal box
Prince William and his wife Catherine watch Roger Federer against Mikhail Youzhny in the Royal Box at Wimbledon.
"My life is complete!," tweeted German women's player Anna-Lena Groenefeld.
"I don't care that we won the Mixed! Prince William said hi to me! I was so excited I won my service game!????"
Also in the Royal Box were Rod Laver, Andre Agassi and wife Steffi Graf.
England football manager Roy Hodgson, whose side crashed out of Euro 2012 in the quarter-finals against Italy last month, was also in the box watching the men's action with his wife Sheila.
Last week, William's father Prince Charles visited the tournament for the first time since 1970. He was joined by his wife Camilla, the Duchess of Cornwall.