Valmiki Ramayana Bala Kanda Sarga 1 Shloka 69

तदा then, ताराम् Tara (Vali's wife), अनुमान्य having convinced, सुग्रीवेण Sugriva, समागत: joined (entered into a combat), राघव: Raghava, तत्र there, एनम् him, एकेन with one, शरेण च single shaft, निजघान killed.

After convincing his wife Tara, who was dissuading from this, Vali entered into a combat with Sugriva. There, Rama killed Vali with a single shaft.