Complex sentence: Harvey reprised his role as Joe Lampton in "Life at the Top" (1965), then he enjoyed a big hit with "Darling" (1965), co-starring Julie Christie and Dirk Bogarde.
Split into simpler sentences: Harvey reprised his role as Joe Lampton in "Life at the Top" (1965). Harvey starred in "Darling" (1965) and co-starred with Julie Christie and Dirk Bogarde.