In stage 21, the weather conditions were bad. Before the stage started, Gaul told Bobet that he would attack on the first climb of the day, which he did. Bahamontes followed him, but let himself drop back because the weather was too bad and the finish was still far away. Gaul continued on his own, and his margin with the next cyclist kept growing. Géminiani now asked the French national team to help him, but they could not help and did not want to help. Géminiani forgot to take food in the food zone, and was hungry in the last part of the stage. In the end, Gaul won the stage almost 8 minutes ahead of the next rider. Favero came in third, more than ten minutes later, and Géminiani seventh more than 14 minutes behind. Favero was again first in the general classification, with Géminiani only 39 seconds behind in second place and Gaul 67 seconds behind in third place. After that stage, Géminiani accused the French team of treason, because he said it was due to their attacks that he lost the lead. Because of the extraordinary circumstances, the time limits were not enforced that stage. Second-placed rider Favero was now at a margin of more than three minutes.