The hand that gives one the edge (5)

I believe the answer is:

upper

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'the edge' is the definition.
(thesaurus)

I cannot understand how the rest of the clue works.

(Other definitions for upper that I've seen before include "form of stimulant" , "Pep pill" , "Higher in rank" , "Higher; part of shoe" , "Section of Oxford" .)

I've seen this clue in The Hindu.

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