Baali was famous for the boon that he had received, according to which anyone who fought him in single-combat lost half his strength to Baali, thereby making Baali invulnerable to any enemy.
Ram encouraged Sugriv to challenge Baali for a duel and bring him outside Kishkindha. Accordingly a duel ensued wherein Baali assaulted Sugriv and chased him off.
Sugriv asked Ram why he did not come to his rescue. Ram told that he could not make out difference between the two brothers for they were alike.
Ram asked Sugriv to wear a flower garland as a mark of identification between the two brothers and again challenge Baali, so with that identification of garland he could aim his arrow at the other dueler.