Steffi Graf plays tennis.
Steffi Graf . In 1988 , she became the first and only tennis player ( male or female ) to achieve the Golden Slam by winning all four Grand Slam singles titles and the Olympic gold medal in the same calendar year . Furthermore , she is the only tennis player to have won each Grand Slam event at least four times . She and Margaret Court are the only players , male or female , to win three grand slams in a calendar year five times ( 1988 , 1989 , 1993 , 1995 and 1996 ) . Graf is regarded by some to be the greatest female tennis player of all time .