Sugriva was so afraid of Bali that he went away to live in a hill called Rishyamukha with his minister, Hanuman. Sugriva chose to live on Rishyamukha, because Bali was cursed regarding the hill. If Bali ever set foot on the hill, his head would burst. So Bali never went near Rishyamukha.
Rishyamukha: This kingdom is identified to be the regions around the Tungabhadra river (then known as Pampa Saras) near Hampi and belongs to Koppal district, Karnataka
However, Bali hated Sugriva so much that he thought night and day only of how he could cause trouble for Sugriva. Then finally, one day he got an idea.
Each day, Bali flew through the sky and bathed in the four oceans. One day, as he was on his way back, he flew very low over Sugrivas hill, swooped down, and kicked Sugriva on his head, BANG, without setting foot on the hill. Then Bali very quickly flew away. This went on for many days. OOH! AAH! OUCH! Sugriva cried out in pain every day as he was kicked by Bali. Then he would try to run and search for another hiding place on the hill. But Bali would always find it the very next day, and once again kick Sugrivas head.
When he saw this, Hanuman got very angry indeed. He decided, the next time Bali comes to torment my king, I’ll seize him and make him touch the ground. Then, his head will burst out into pieces according to the curse.
So, the next time when Bali flew down to kick Sugriva, Hanuman grabbed him by his waist. He pulled Bali down with all his strength, and tried to make Bali’s feet touch the ground. But mighty Bali resisted and leapt upwards. Would Hanuman leave Bali so easily? No! Hanuman used all his strength to pull Bali down. This fierce tug-or-war lasted for hours. Neither of the two parties could win. At last Bali pleaded with Hanuman, Please Hanuman, let me go! I promise I’ll never again hurt your king Sugriva. This was what Hanuman wanted to hear. Ok, you may go, he said, and he released Bali from his grip. Bali returned to Kishkindha quietly. Sugriva and Hanuman lived in peace on Rishyamukha hill ever after, without having any trouble from Bali.