Started in rallies but switched to sports cars, winning at Spa in 1949 and Montlhery in 1950. Badly injured in the Moroccan GP of 1956, he turned to administrative roles within the sport as well as co-founding the magazine Sport-Auto.
Turning to racing after beginning his career in rallies, Jean recorded his best results behind the wheel of sports cars, winning at Spa in 1949 and Montlhery the following year in Luigi Chinetti's Ferrari. In 1953 Lucas joined Gordini as team manager and occasional driver, though he was still to be seen racing his own Ferrari under the Los Amigos banner in North African events such as those held at Agadir and Marrakesh which were popular at the time. It was only when urgent business matters called Manzon away from the Monza circuit that Lucas stood in to make his solitary World Championship appearance.
In 1956 he took an old Ferrari 625 to fifth place in the Caen GP, and in 1957 he finished second in the F2 Coupe de Vitesse at Reims in Alan Brown's Cooper. He also took third place in his Los Amigos Jaguar D-Type at Le Mans that year, but driving du Puy's Maserati 250F in the end-of-season Moroccan GP he overturned the car and was badly injured.
Realising that he would not be able to race again to his fullest abilities, he threw himself into administrative roles within the sport as well as co-founding the magazine Sport-Auto with Gerard Crombac in 1962, moving on to other publishing projects when his interest in motor sport had waned.