Chinese Revolution topping the bill, alas, ultimately for communist (6)
I believe the answer is:
engels
'communist' is the definition.
(I've seen this before)
'chinese revolution topping the bill alas ultimately' is the wordplay.
'ultimately' suggests the final letters.
The final letters of 'chinese revolution topping the bill alas' are 'ENGELS'.
'for' acts as a link.
(Other definitions for engels that I've seen before include "Communism founder" , ". . . and his friend, Friedrich" , "Friedrich .. . . . . founded communism with Karl Marx" , "Marx's co-author" , "Marx's patron" .)