Graf， Steffi （1969- ）， German professional tennis player， who in 1988 became only the fifth player to win the grand slam of tennis， with victories at the Australian Open， the French Open， Wimbledon， and the United States Open in one calendar year. Graf was born in Brühl， West Germany （now part of Germany）。 Coached by her father， Peter， a soccer star， and encouraged by her tennis-playing mother， Heidi， she was already playing tennis at the age of six. In 1982， at the age of 13， Graf became the second-youngest tennis player ever to be ranked as a professional.
By 1985 Graf had reached the number-six ranking， but she had not yet won a tournament. In 1986， however， she won eight singles championships， including victories in tournament finals over the dominant players in women's tennis， Martina Navratilova and Chris Evert. In 1987 Graf won 45 consecutive matches and captured 11 tournaments， including the French， Italian， and German opens and the Women's International Tennis Association's indoor and outdoor championships. In 79 matches that year， her only losses were to Navratilova in the finals at Wimbledon and the U.S. Open.
In 1988， by winning Wimbledon and the Australian， French， and U.S. opens， Graf became the fifth player to achieve the grand slam， following Don Budge in 1938， Maureen Connolly in 1953， Rod Laver in 1962 and 1969， and Margaret Smith Court in 1970. Graf also won the gold medal at the Olympic Games in Seoul， South Korea. She opened 1989 with a fifth consecutive grand-slam tournament victory by winning the Australian Open. She did not win the French Open in 1989， but she retained her titles at Wimbledon and the U.S. Open. In 1990 she won the Australian Open， and in 1991 she won Wimbledon. She repeated her Wimbledon title in 1992， also winning the silver medal at the 1992 Olympics in Barcelona， Spain， losing in the final to American player Jennifer Capriati. In 1993 Graf won three grand slam tournaments —— Wimbledon and the French and U.S. opens. In 1994 she won the Australian Open. The following year she again won Wimbledon and the French and U.S. opens. She continued her success into 1996， repeating her titles at all three events.
Although both suffered numerous injuries， Graf and Serbian-born player Monica Seles developed a rivalry in the early and mid-1990s as the world's two best female players. In early June of 1999， she again won the French Open singles title in Paris， defeating top-seeded Martina Hingis of Switzerland on June 5， losing the first set 6-4 before winning the last two， 7-5 and 6-2.