Needing no introduction, top series set apart (8)

I believe the answer is:

estrange

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'set apart' is the definition.
(thesaurus)

I cannot understand how the rest of the clue works.

(Other definitions for estrange that I've seen before include "Arouse hostility" , "Get on the wrong side of" , "turn away?" , "Anger set (anag.)" , "Become unfriendly towards sergeant" .)

I've seen this clue in The Times.

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