Strasbourg beat Bourg Peronnas 2-1 on Friday to secure promotion while a 96th-minute winner ensured Amiens will join them in France's top division next season.
Emmanuel Bourgaud scored a dramatic winner deep in stoppage time as Amiens beat Reims 2-1, denying Lens, Brest and Nimes promotion on the final day.
Aboubakar Kamara gave Amiens the lead in the 13th minute but Diego equalized in the 61st for Reims.
Kader Mangane scored in the 15th and an own goal four minutes later allowed Strasbourg to secure the championship with 67 points.
Third-placed Troys had looked to secure an immediate return to the top flight after a 3-2 win over Sochaux, but heads to a playoff with the 18th-placed side in the top division later this month.