L.Hewitt fast? Leg broken in big annual race? (3,7,4)

I believe the answer is:

the stawell gift

I'm a little stuck... Click here to teach me more about this clue!

'big annual race?' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'l hewitt fast? leg broken' is the wordplay.
'broken' indicates anagramming the letters.
'l'+'hewitt'+'fast'+'leg'='lhewittfastleg'
'lhewittfastleg' is an anagram of 'THE STAWELL GIFT'.

'in' is the link.

Can you help me to learn more?

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

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