To the contrary, in the Iliad, Homer mentions Achilles being wounded: in Book 21 the Paeonian hero Asteropaios, son of Pelagon, challenged Achilles by the river Scamander.
tə ðə kˈɑːntɹɛɹi, ɪnðɪ ˈɪlɪˌæd, hˈoʊmɚ mˈɛnʃənz ɐkˈɪliːz bˌiːɪŋ wˈuːndᵻd: ɪn bˈʊk twˈɛnti wˈʌn ðə piːˈoʊniən hˈiəɹoʊ ˈæstɚɹˌɑːpeɪˌoʊz, sˈʌn ʌv pˈɛlæɡən, tʃˈælɪndʒd ɐkˈɪliːz baɪ ðə ɹˈɪvɚ skˈæmændɚ.