Final answer:
According to Inca legend, Yupanki came to power in Cuzco as a result of his victory in a battle against the Chanka. The story tells of his courage and divine intervention that aided him in defeating the Chanka and assuming control of Cuzco and the Inca Empire.
Step-by-step explanation:
According to Inca legend, Yupanki came to power in Cuzco as a result of his victory in a battle against the rival group known as the Chanka. When the Chanka attacked Cuzco, the reigning king fled, leaving Yupanki and a small group of nobles to defend the city. Yupanki's courage inspired the creator god of the Inca to transform the surrounding stones into warriors who helped Yupanki defeat the Chanka. After the victory, Yupanki assumed the additional title of Pachacuti and became the ruler of Cuzco and the Inca, marking the beginning of the Inca Empire.