lˈaɪɑːn ɪmpɹˈuːvd ɪn tˈuː θˈaʊzənd fˈaɪv, kənvˈɜːɾɪŋ fˈoːɹtiːn sˈeɪvz ɪn fˈɪftiːn ɑːpɚtˈuːnᵻɾiz wˌaɪl pˈɪtʃɪŋ ɪn θˈɜːɾi tˈuː ɡˈeɪmz ænd spˈɛndɪŋ pˈɑːɹt ʌvðə sˈiːzən æz ðə dˈaɪəməndbˌæks klˈoʊsɚ, ɹᵻplˈeɪsɪŋ ðɪ ˈɪndʒɚd hoʊsˈeɪ vˈælvɚd.
Lyon improved in 2005, converting 14 saves in 15 opportunities while pitching in 32 games and spending part of the season as the Diamondbacks' closer, replacing the injured José Valverde.