 After leaving Manfred Mann's Earth Band in 1978, he briefly toured as a temporary member of Thin Lizzy after Gary Moore left the group following a concert on 4 July 1979.After Midge Ure initially replaced Moore, Flett was recruited in early September 1979 as lead guitarist alongside Scott Gorham for a tour of Japan, while Ure switched to keyboards.Playing his first show with Thin Lizzy in Osaka on 24 September, Flett performed at five shows before the band returned home.