Old woman made ground stroke - equalling score? (6,9)

I believe the answer is:

madame butterfly

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

'equalling score?' is the definition.
I can't judge whether this definition defines the answer.

'old woman made ground stroke' is the wordplay.
'old woman' becomes 'ma' (both can mean someone's mother).
'ground' indicates anagramming the letters ('grind' the letters into a new form).
'stroke' becomes 'butterfly' (type of swimming stroke).
'made' anagrammed gives 'dame'.
'ma'+'dame'+'butterfly'='MADAME BUTTERFLY'

Can you help me to learn more?

(Another definition for madame butterfly that I've seen is " opera".)

I've seen this clue in The Independent.

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