Dupuis began playing tennis at the age of nine with his father Xavier.

He mentioned in an interview once that he prefers clay and hard court surfaces.

He was coached by Benoit Carelli, whom he credits with improving his physical and mental ability.

[1][2] In 2005, at the Valencia tournament, Dupuis became the first French player to defeat Novak Djokovic.

In 2006 he tested positive for the banned drug Salbutamol and was suspended for two and a half months.