Gustavo Kuerten. Gustavo "Guga" Kuerten is a Brazilian former professional tennis player. He was ranked as the world No. 1 in men's singles by the Association of Tennis Professionals for 43 weeks, including as the year-end No. 1 in 2000. Kuerten won 20 ATP Tour-level singles titles, including three majors at the French Open in 1997, 2000, and 2001, as well as the 2000 Tennis Masters Cup. He also won eight doubles titles.
