Prof. Dr. Satya Vrat Shastri's Thai Ramayana 19. Sugriva has his revenge and Hanuman sets Lanka ablaze.

Sugriva was thrown out by Valin without being allowed to explain. This harsh treatment upset Sugriva as he felt that he was blamed without reason. In anger he requested Rama to kill his brother. In return he offered Rama  refuge and promised his support. Rama the brave one, asked Sugriva to challenge Valin for a duel. Sugriva did accordingly and Valin accepted.

As the duel was on, Rama from behind a tree killed the fierce-minded elder brother of Sugriva and crowned Sugriva the king. The king keeping in mind the very good turn done to him, showed his gratitude by promising Rama help for the recovery of Sita. He also induced Valin's son Angada and others like Nilaphad to help Rama.

The entire vast army of Sugriva looking like a river reached the shore of the ocean with a mind to conquer the city of Lanka. Then the wise Hanuman went to Lanka and saw Sita. He gave her the ring given to him by Rama. While returning from there he set Lanka ablaze with his tail which was set on fire by the cruel demons.

Thereafter the wise monkey met Rama and gave him the entire story of his visit to Lanka. Rama surrounded by his allies and with a sense of discrimanation got ready to attack Ravana.