Stefanie Maria "Steffi" Graf (born 14 June 1969) is a German former tennis player who was ranked world No. 1 during her career. She won 22 Grand Slam singles titles, tied with Serena Williams for the joint record since the Open Era began in 1968, and ranks second all-time behind Margaret Court (24). In 1988, Graf became the first and only player to achieve the Golden Slam by winning all four Grand Slam singles titles and the Olympic gold medal in the same calendar year. She is also the only player to have won each Grand Slam event at least four times.
Graf was ranked World No. 1 by the WTA for a record 377 weeks, the longest period for any player since rankings began. She won 107 singles titles, ranking third on the WTA all-time list. Graf and Margaret Court are the only players to win three Grand Slams in a calendar year five times. Graf excelled on all surfaces, winning each of the four Majors at least four times. She won six French Open titles, seven Wimbledon titles, four Australian Open titles, and five US Open titles. Graf reached thirteen consecutive Grand Slam finals from 1987 to 1990 and appeared in a total of 31 Grand Slam finals. She retired in 1999 while ranked No. 3, married Andre Agassi in 2001, and was inducted into the Tennis Hall of Fame in 2004.
Germany