Goddess Parvati instructed her son, the elephant-headed god Ganesha, not to allow anyone to disturb Lord Shiva's meditation. Just then, Parashuram arrived at Mount Kailash to meet his former teacher, Shiv. He ran into Ganesha, who did not allow him to proceed further. Ganesha told Parashurama, "I am Shiva and Parvati's son," but Parashurama did not believe him because of his elephant head.
Parashurama and Ganesha began to fight. They were evenly matched, shooting arrows at each other. The omniscient Lord Shiva knew that his son and former pupil were fighting but chose not to intervene. Finally, Parashurama flung his axe at Ganesha. Out of respect for the axe, which had been presented to Parashurama by none other than Lord Shiva, Ganesha did not try to defend himself; therefore, the axe broke his left tusk.
Ganesha howled in pain, drawing Parvati to the battlefield. Seeing Ganesha's broken tusk on the ground, she threatened to punish Parashurama for injuring her son. When Parashurama realized that Ganesha was indeed the son of Shiva and Parvati, he profusely apologized. Shiva arrived at the scene and advised Parvati to forgive Parashurama. He also said that Ganesha would henceforth be worshipped as Ekadanta, meaning "the single-tusked one."