 Ironically, after gaining more experience he appeared less for the first team, eventually leaving in the summer of 1995.After one year in FC Martigues, Flachez joined FC Sochaux-Montbéliard, where he would remain for eight straight seasons always as an undisputed starter (four years apiece in the top flight and Ligue 2), playing more than 300 competitive matches.In 2002–03 he helped the team finish fifth and reach the final of the Coupe de la Ligue; as the latter competition winners AS Monaco FC ranked second in the league and qualified for the UEFA Champions League, Sochaux qualified for the UEFA Cup, where the player took part in his first matches (six).