Ramayana
असुरा दानवाश्चैव सत्त्ववन्तो महाबलाः । सर्वे समरमासाद्य न श्रूयन्ते ऽपराजिताः ॥ 7-6-36 ॥
Those Asuras and Danavas too, full of valor and of great strength — not one of them, having come into battle, is ever heard to have gone unvanquished.
english translation