Valmiki Ramayana Kishkindha Kanda Sarga 57 Shloka 19

ततः then, राघवः Rama, मम my, पितृव्येण with my father's brother, महात्मना by the great self, सुग्रीवेण with Sugriva, सख्यम् friendship, चकार made, सः he, Rama, पितरम् my father, अवधीत् killed.

'Then Rama made friendship with my father's brother, great self Sugriva and killed my father.