London - Serena Williams joined the Wimbledon tributes to ailing former South Africa president Nelson Mandela on Tuesday, claiming it was one the greatest moments of her life when she met the anti-apartheid icon.
The American described Mandela, who is critically ill in a Pretoria hospital, as an "amazing" man from whom lessons can be learned.
"It's a really sad time I think for everyone. I feel like Nelson Mandela lived a really amazing life.
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"Meeting him was probably one of the best moments of my life, and it will be a great loss," said the Wimbledon champion.
Williams said she started reading Mandela's acclaimed autobiography, Long Walk to Freedom, after returning from South Africa on her most recent visit last year.
"He's had a great story.
"I think everyone of all races and nations and countries and individuals can learn from his stellar life," she said.
"I think his whole example is an extremely important part of our lives.
"For someone to have been incarcerated for so long and then have such a forgiving heart, to have such an open heart, open spirit, open soul is unheard of.
"I think we, as a people, can learn from the courage, the faith, and everything that Nelson Mandela has."