A few sports stars win something rarer than trophies or championships - an enduring place in the public's affections. Steffi Graf is one of them. She hung up her racket five years ago after winning an amazing 22 Grand Slam titles, but that doesn't mean she is any less busy or beloved. Married since 2001 to fellow tennis champ Andre Agassi, the seven-time Wimbledon winner devotes much of her time these days to son Jaden Gil, 3, and daughter Jaz, 1 - and much of the rest to kids far less fortunate than hers. Both in her native Germany and in projects in Kosovo, Mozambique and South Africa, a nonprofit founded by Graf helps thousands of kids traumatized by war, persecution, violence and exile. "I've always felt very protective of kids," says Graf, 35. "Maybe it will be able to change at least some children's lives for the better." It's a goal as powerful and direct as her approach to tennis, and to life.

In the 1990s, Graf got to know the work of psychiatrists at the Outpatient Clinic for Refugee Children and their Families at the University of Hamburg-Eppendorf. With them, she funded a charity called Children for Tomorrow in 1998. "[These children] have been overlooked for so long," she says. "So I thought I'd see if I can bring awareness to the subject, and maybe help on starting some projects." That work proved to be both satisfying and heartbreaking. Dropping in on the Cape Town project, for instance, she was moved by the children's cheerfulness in the face of misery. "These kids have nothing, they've been abused and abandoned and thrown on garbage heaps," Graf remembers. "And still they come to you and even have big smiles on their faces."

She brings to the task the same energy and concentration that once helped her dominate women's tennis like no player before or since. During her professional career, which started in 1982 and ended in 1999 after a long battle with injuries, the woman whom many Germans still fondly call Fräulein Forehand won an Olympic gold medal in Seoul in 1988 plus 106 other international singles tournaments. Martina Navratilova and Chris Evert may be ahead of her in total singles wins, but for her sheer persistence and dominance of her sport - she was ranked No. 1 for a record 377 weeks - many consider Graf the greatest female tennis player ever. "I love to work out, I love to run, to be physically challenged," she muses, "and tennis was perfect for that."

Other challenges came off court. In 1993, a disturbed Graf fan stabbed Monica Seles and professed to have done it for his idol; he was sentenced to two years' probation. Her father, Peter, who introduced her to the sport, was convicted of tax evasion in 1997. She refused to let these shocks interfere with her game or her drive. "There is a reason you go through different things in life, and they make you who you are," she says. "So I don't fight the tough times. I try to understand them, and I try to work through them." Her country has stuck by her. This spring, in a poll published by TV magazine tv14, Graf was voted "the Germans' greatest role model" for her trustworthiness and authenticity. "I've always wanted to see if I could make a difference in somebody else's life in a positive way," she says. Few would argue that she hasn't.