Serena Williams called her meeting with Nelson Mandela, "probably one of the best moments of my life." Roger Federer noted Mandela's "amazing personality," and Maria Sharapova preferred instead to celebrate Mandela's life.

The world mourned the death of South African president Nelson Mandela on Friday. While his life had a global impact, the tennis world isn't the first group that comes to mind when talking about Mandela's influence.

But when the anti-apartheid leader became critically ill during the summer, some of tennis' biggest stars paid tribute to Mandela.

One of the more touching tributes came from Williams, whom multiple media reports said became emotional when talking about him.

"I think his whole example is an extremely important part of our lives,'' she said, according to msn.foxsports.com, noting that Williams became choked up when asked about him. "For someone to have been incarcerated for so long . . . to have such an open heart, open spirit, open soul is unheard of.

"I think we, as a people, can all learn from the courage, faith and everything that Nelson Mandela has."

Williams did not specify when she met Mandela, msn.foxsports.com reported, but the encounter obviously moved her.

""Just meeting him, speaking to him ...'' she said. "He's so coherent, he's so smart, he's so amazing. . . . Where he started as a kid, then going from there, making his way really to the top of something completely inconceivable. Having so many people love him and cherish him for who he was, for being black, for being in South Africa at a time where maybe it wasn't the best moment to be black in South Africa.

"He's had a great story. I think everyone of all races and nations and countries and individuals can learn from his stellar life."

Federer referred to Mandela as the ideal role model, according to SI.com: "He's been very influential, amazing personality, you know, believed in something, had to pay a big price for it. Someone you can definitely look up to. And that's, for me, very important people in this world. Clearly, there's many that come and go, but he has been there for a very long time. And he's very much respected and loved."

SI.com also reposted a quote from Sharapova: "I think it should be a celebration of what he accomplished in his life than a sadness, even though many people around the world are sad about it ... ."

Now-retired American James Blake also marveled at Mandela's life story.

"You know, we're out here and we think we're doing something important playing a tennis match," msn.foxsports.com reported him as saying. "And it puts it into perspective when someone has such a belief that they're willing to go to jail for it. They're willing to fight for it. Then in the end, they change a country and in turn change the world. That's something that for me, I can't fathom having that kind of effect on the world."