After being appointed to Umanosuke, Asatsune smoothly made his career as military officer, namely he was appointed to Saemon no suke (assistant captain of the Left Division of Outer Palace Guards) in 991, promoted from Jugoinoge (Junior Fifth Rank, Lower Grade) to Jugoinojo (Junior Fifth Rank, Upper Grade) in 993 and was appointed to Ukon no gon no shosho (Minor Captain of the Right Division of Outer Palace Guards) in the following year.
右馬助任官後、朝経は正暦2年（991年）には左衛門佐、正暦4年（993年）には従五位下から従五位上、翌年には右近権少将と、武官系の閲歴を順調に重ねていた。