King of the Cup, Simpson, with Latin men in Gateshead son! (4,8)

I believe the answer is:

bart cummings

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'king of the cup' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'simpson with latin men in gateshead son' is the wordplay.
'simpson' becomes 'Bart' (Bart Simpson, The Simpsons character).
'with latin men in' becomes 'cummin' (I am not sure about this - if you are sure you should believe this answer much more).
'gateshead' becomes 'g' (head letter of 'gates').
'son' becomes 's' (genealogical abbreviation for son).
'bart'+'cummin'+'g'+'s'='BART CUMMINGS'

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I've seen this clue in the Sydney Morning Herald.

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