Larsson turned professional in 1989 and won his first top-level singles title at
Florence in 1990. His first doubles title was also won in Florence, in 1991. Some of the most significant highlights of Larsson's career came in 1994. He won that year's
Grand Slam Cup, defeating World No. 1
Pete Sampras in the final in four sets 7–6, 4–6, 7–6, 6–4. Larsson also reached the semi-finals of the
1994 French Open, and was part of the
Swedish team which won the
1994 Davis Cup. He won singles rubbers in the Davis Cup final in Moscow in December against both
Yevgeny Kafelnikov and
Alexander Volkov, as
Sweden defeated
Russia, 4–1. In 1995, Larsson reached his career-high singles ranking of World No. 10 and his career-high doubles ranking of World No. 26. He was runner-up in the men's doubles at the French Open that year (partnering
Nicklas Kulti). He was also part of the Swedish team which won the
World Team Cup. Larsson played in the final of the Davis Cup again in 1997. And again he won both his singles rubbers – against Pete Sampras and
Michael Chang – and was on the winning team as Sweden thrashed the
United States 5–0. Larsson won a total of seven singles and six doubles titles during his career. His last doubles title was won in 1998 in
Båstad. His final singles title came in 2000 at the
Regions Morgan Keegan Championships in
Memphis. He retired from the professional tour in 2003. He has since played in the senior
Outback Champions Series, winning the
Stanford Championships in 2006. ==Junior Grand Slam finals==