Stefanie Maria Graf, known professionally as Steffi Graf and preferring to be called Stefanie since 2001, is a German former professional tennis player. She was ranked as the world No. 1 in women's singles by the Women's Tennis Association (WTA) for a record 377 weeks, and finished as the year-end No. 1 a record eight times. Graf won 107 singles titles on the WTA Tour, including 22 major women's singles titles, the second-most since the start of the Open Era in 1968 and the third-most of all time. She is the only tennis player to have won each major singles tournament at least four times—a quadruple career Grand Slam. WTA world No. 1 from June 12, 1995 to August 14, 1995 — 9 weeks. Wiki link