Mark on head of horse for leading performer (4)

I believe the answer is:

star

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This clue might be a double definition.

'mark on head of horse' is the first definition.
'star' can be an answer for 'mark' (I know that star is a type of mark). I'm not sure about the 'on head of horse' bit.

'leading performer' is the second definition.
(I've seen this before)

'for' is the link.

Can you help me to learn more?

(Other definitions for star that I've seen before include "One guiding" , "For example, Marilyn Monroe" , "Lead actor" , "virtuoso" , "Symbol of excellence" .)

I've seen this clue in The Telegraph.

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